2015-16 MLB Offseason Moves GMs Should Wish They Could Have Back

With unbridled optimism running rampant among the fanbases of all 30 MLB teams, it's relatively easy to spin most offseason moves in a positive light.

For contenders, it's not difficult to view a few key veteran additions as the missing pieces to bridge the gap to World Series appearances.

For rebuilding clubs, prospect additions immediately become the next big thing for the organization as the fanbase keeps an eye on the future and brighter days ahead.

However, sometimes a deal just looks like a mistake.

Whether giving up too much in a trade, overpaying for a free agent or cutting ties with someone a team should have retained—there are always at least a few offseason transactions that look regrettable almost immediately.

The Deal

Transaction: SP/RP Yusmeiro Petit is non-tendered

Why It Warrants a Mulligan

Consider, if you will, the following hypothetical, but very possible, series of events:

• 1. Matt Cain fails to stay healthy and hold down a spot in the rotation

Once one of the best pitchers in the National League, Cain has dealt with injuries the past two seasons to make 26 combined starts while posting a 4.83 ERA.

The 31-year-old is penciled into the No. 5 spot in the rotation, but he's far from a sure thing.

• 2. Another starter gets hurt

Newcomer Johnny Cueto has dealt with injuries in the past, and 34-year-old Jake Peavy made just 19 starts last year, so having another starter miss time is a real possibility.

• 3. Chris Heston regresses in his sophomore season

Chris Heston would appear to give the team some useful depth after going 12-11 with a 3.95 ERA in 31 starts as a rookie, but he hit a wall in the second half with a 5.94 ERA in his final 10 starts.

He'll likely start the year as the team's long reliever and next man up if the rotation needs a spot starter, but he's a question mark as well.

So, what does all of that add up to? 

Potentially, a sorely missed swingman by the name of Yusmeiro Petit.

Over the past two seasons, Petit has made 13 starts and 68 relief appearances for the Giants, going a combined 6-6 with a 3.68 ERA, 1.083 WHIP and 192 strikeouts in 193 innings of work.

Despite those numbers and a reasonable projected arbitration salary of $2.4 million, the Giants opted to non-tender the 31-year-old.

He ended up signing with the Washington Nationals for $2.5 million, and cutting him loose could wind up being a rare mistake by the Giants' front office.

The Deal

To TOR: SP/RP Jesse Chavez
To OAK: RP Liam Hendriks

Why It Warrants a Mulligan

Marco Estrada began the 2015 season expected to fill a swingman role for the Toronto Blue Jays, but he quickly won a spot in the starting rotation and wound up being their most reliable starter.

Now that he's cemented his place in the rotation, adding a capable long reliever was among the Blue Jays' offseason needs, and they quickly found their man in Jesse Chavez.

The 32-year-old Chavez went 15-23 with a 3.83 ERA and 1.330 WHIP in 47 starts and 15 relief appearances in 2014 and 2015. While he's a useful arm capable of filling a number of roles, he doesn't provide much in the way of upside and is headed for free agency next winter.

In exchange, the Blue Jays sent hard-throwing righty Liam Hendriks to the Oakland Athletics, and Toronto will no doubt miss his power arm.

Per FanGraphs, the 26-year-old saw his fastball velocity increase from 91.3 mph in 2014 to 94.9 mph this past season, and his performance took off as a result.

In a career-high 58 appearances, he posted a 2.92 ERA and 1.082 WHIP while striking out 71 batters in 64.2 innings of work.

The real kicker here is the fact that Hendriks is under team control through the 2019 season, so Toronto essentially traded four seasons of a quality late-inning reliever for one year of a decent swingman.

The Deal

Contract: Three years, $22 million

Why It Warrants a Mulligan

Overhauling the bullpen was more necessity than strategy for the Oakland Athletics this offseason.

The relief corps ranked dead last in the American League and 28th in the majors with a 4.63 ERA, converting just 28 of 53 save chances in the process.

That all added up to a dismal 19-35 record in one-run games, and the team has added a number of arms to the mix this winter in an effort to rectify that situation.

One such addition was veteran Ryan Madson, who was signed to a three-year, $22 million deal as one of the top relievers on the free-agent market.

That may not seem like a huge investment at first blush, but for a small-market team like Oakland, that $7 million salary in 2016 is enough to make Madson the fourth-highest-paid player on the team, per Roster Resource.

The 35-year-old posted a 2.13 ERA, 0.963 WHIP and 8.2 strikeouts per nine innings with 20 holds this past season, a great season by all accounts.

However, we're also talking about a player who had missed three consecutive seasons prior to 2015 while dealing with various arm issues.

Given his age and medicals, Madson is a risk on a three-year deal, and that risk is only amplified by Oakland's significant salary restrictions.

One year after watching the team cut ties with Josh Donaldson in an effort to save money, it's tough to justify spending that kind of dough on a risky setup reliever.

The Deal

Contract: Two years, $18.5 million

Why It Warrants a Mulligan

Sometimes, statistics really do tell the story.

With that in mind, let's do a blind comparison of two players:

• Player A: .263/.295/.408, 22 2B, 16 HR, 59 RBI, -10 DRS, -3.3 UZR/150

This player is 24 years old, and the numbers above represent his first extended MLB action.

He is still pre-arbitration this season and probably won't make much more than $2.5 million in his first year of eligibility next winter, putting him somewhere in the $3 million ballpark for the next two seasons.

• Player B: .265/.315/.430, 28 2B, 15 HR, 58 RBI, -7 DRS, -10.4 UZR/150

This player is 30 years old, and the numbers above represent more or less the same level of production we've seen from him each of the past four seasons.

He was signed to a two-year, $18.5 million deal in free agency to replace Player A by a team that doesn't really qualify as "small market" but has its own unique brand of financial limitations.

Player A is Wilmer Flores. Player B is Asdrubal Cabrera.

The Mets managed to find a way to re-sign Yoenis Cespedes, so the financial question marks of this move don't loom quite as largely.

However, it still comes across as a sideways move with an unnecessarily high price tag.

The Deal

To SEA: SP Wade Miley, RP Jonathan Aro
To BOS: RP Carson Smith, SP Roenis Elias

Why It Warrants a Mulligan

With J.A. Happ traded at the deadline and Hisashi Iwakuma set to sign with the Los Angeles Dodgers, the Seattle Mariners were in the market for a starting pitcher during the winter meetings.

The Boston Red Sox were looking to move a starter after signing David Price, and the two teams worked out a deal that sent left-hander Wade Miley and a prospect to the Mariners in exchange for Carson Smith and Roenis Elias.

Smith, 26, showed closer stuff as a rookie last year when he recorded 13 saves with a 2.31 ERA, 1.014 WHIP and 11.8 K/9. He comes with five remaining years of team control and should have been a key piece of the Mariners' bullpen going forward.

For comparison's sake, the Philadelphia Phillies moved a similar player with the same amount of team control in Ken Giles and picked up a package of five pitchers in return, including the highly regarded duo of Mark Appel and Vincent Velasquez.

Elias was by no means a throw-in either, as the 27-year-old went 15-20 with a 3.97 ERA and 1.308 WHIP in 51 games (49 starts) over the past two seasons and also came with five years of control.

The deal looked lopsided at the time but now looks largely unnecessary after Iwakuma's deal with the Dodgers fell apart due to issues with his physical. He wound up back in Seattle on a one-year deal.

"No question the Mariners’ trade for Miley...was a direct reaction to their belief they had lost Iwakuma," wrote Larry Stone of the Seattle Times.

It was an unforeseeable series of events that has given the Mariners some solid rotational depth, but subtracting Smith from the bullpen in the process is going to hurt.

The Deal

To LAA: SS Andrelton Simmons, C Jose Briceno
To ATL: SP Sean Newcomb, SP Chris Ellis

Why It Warrants a Mulligan

The Los Angeles Angels led all of baseball with 4.77 runs per game in 2014, but they saw that number plummet to 4.08 runs per game in 2015 to rank 20th in the league.

Despite a clear need for significant offensive upgrades at a number of positions, the team's big move of the offseason was acquiring shortstop Andrelton Simmons.

The pitching staff will love having the defensive whiz flanking them, but is a career .256/.304/.362 hitter really what the team needed to aid its offensive woes?

"They got the best defensive shortstop in the game—innumerate postseason awards be damned—but gave up their top two prospects for him, which hampers their ability to make any other significant moves this winter without spending a lot of cash," wrote ESPN Insider Keith Law.

And indeed he was right. The team's biggest additions outside of Simmons have been the likes of Yunel Escobar, Daniel Nava, Craig Gentry and Geovany Soto.

Meanwhile, it cost an already incredibly thin Angels farm system what was widely considered to be its two best prospects in Sean Newcomb and Chris Ellis.

Newcomb, 22, went 9-3 with a 2.38 ERA, 1.272 WHIP and 168 strikeouts in 136 innings last season while reaching Double-A. He checks in as the No. 21 prospect in the league, according to MLB.com's Prospect Watch.

Ellis, 23, saw his stock rise this past year after he went 11-9 with a 3.90 ERA and 132 strikeouts in 140.2 innings while also reaching Double-A.

That's a steep price to pay for a one-dimensional player, even if he is the game's best defensive shortstop.

The Deal

To ARI: SP Shelby Miller, RP Gabe Speier
To ATL: OF Ender Inciarte, SS Dansby Swanson, SP Aaron Blair

Why It Warrants a Mulligan

The Arizona Diamondbacks began the offseason in clear need of starting pitching after they ranked 23rd in the league with a 4.37 ERA from their starters.

Even after making a splash with the surprise addition of ace Zack Greinke, the staff was still lacking a solid No. 2 starter to round out the rotation if the D-Backs were serious about contending for a postseason spot.

Shelby Miller gave them that No. 2 starter, and a controllable one at that, as he won't reach free agency until after the 2018 season.

His 6-17 record last year was ugly, but it came with a 3.02 ERA (11th in NL), and he was an All-Star for the first time in his career.

Acquiring Miller is not the issue, as he fulfilled a clear need. It was the incredibly steep price the Diamondbacks paid that makes it a regrettable move.

"The cost is comically high," wrote ESPN prospect guru Keith Law immediately following the trade. "They are indeed better, close to playoff contenders at this point, but the long-term cost is just staggering."

Outfielder Ender Inciarte has tremendous value all on his own.

The 25-year-old hit .303 last season and posted a 5.3 WAR thanks to a good combination of speed and defense. On top of those numbers, he's also controllable through the 2020 season, making him a potential long-term piece for the Braves.

On top of that, the Diamondbacks also surrendered the No. 1 overall pick in the 2015 draft in shortstop Dansby Swanson and a quality starting pitching prospect in Aaron Blair.

According to MLB.com's Prospect Watch, Swanson ranks as the No. 8 prospect in the league, while Blair checks in at No. 56 overall.

This was a clear case of the Diamondbacks pushing their chips to the middle of the table and going all-in on their current roster. Time will tell if it was worth it.

All stats courtesy of Baseball-Reference.com, unless otherwise noted.