Stan Wawrinka is seeded second at the Rogers Cup in Toronto as former champions Andy Murray, Roger Federer, and Rafael Nadal are all absent from the tournament due to preparations for the Rio Olympics, however, Wawrinka's compatriot Federer is ruled out for the rest of the year in order to rehab his knee.
Kevin Anderson is unseeded in Toronto this year and has missed a chunk of the ATP World Tour season due to a shoulder injury and during this period whilst he was absent he had minor surgery on his ankle.
Wawrinka, the two-time Grand Slam champion has a chance to overtake Nadal in the ATP World Tour rankings at number four in the world and whilst Federer is out, he will have a good opportunity to return to the top three.
Anderson has dropped out of the top 30 due to missing some events and failing to defend points but the South African is making up for lost time by producing some good tennis and taking advantage of other's injuries.
How they got here
Wawrinka received a bye in the first round and he had a tough opener to begin his quest for the title in the second round. The Swiss number two played former top ten player Mikhail Youzhny, who he hadn't beaten on a hard court prior to this match and he was victorious 7-6, 7-6.
In the third round, Wawrinka recorded another straight sets win over 16th seed Jack Sock 7-6, 6-2.
Anderson's section of the draw has been tough but he has come through it unscathed. The world number 34 defeated Viktor Troicki 7-6, 6-3 in the first round and he drew sixth seed Dominic Thiem in the second round but the young Austrian withdrew from their match when he was 1-4 down.
Anderson came back from a set down to dispatch 12th seed Bernard Tomic 4-6, 6-3, 6-4 to reach the quarterfinals once again in Toronto.
Their history
The Stanimal and Anderson are no stranger to each other as the duo has squared off on eight occasions and their head-to-head is tied at 4 wins apiece.
Wawrinka leads their mini-rivalry 4-3 on hard courts and Anderson leads 1-0 on grass. Six of their eight meetings have taken place on hard court Masters 1,000 events.
The two-time Grand Slam winner won their first three meetings at the Miami Open in 2010, fourth round at the Rogers Cup in 2011 and in the third round in Shanghai in 2013.
Anderson responded by overturning the deficit and won the next four consecutive meetings, starting in 2014 and all three of his victories over Wawrinka were in the fourth round of Masters 1,000 events at the BNP Paribas Open at Indian Wells followed by their meeting two years ago at the Rogers Cup in Toronto and at the BNP Paribas Masters indoors event in Paris.
The big server's most recent victory over Wawrinka was at the Aegon Championships at the Queen's Club in the round of 16 and Anderson went on to reach the final that week, eventually losing to Murray.
Wawrinka gained his first win over Anderson in two years at the US Open last year in the quarterfinals, which was Anderson's first Slam quarterfinal, producing an impressive win over former champion Murray in the previous round. Wawrinka thrashed Anderson 6-4, 6-4, 6-0 to reach his second semifinal in New York.
Who wins?
Both players know each other's game and it depends which Wawrinka turns up on the day. The second seed has a powerful backhand which he can use effectively when he is engaging in a rally and returning Anderson's serve.
Anderson will need to serve well and keep Wawrinka guessing because he will struggle against the two-time Grand Slam champion if his serve isn't working.
The big server is a good returner in his own right but Wawrinka doesn't drop serve often against the big servers and it could be hard for Anderson to break back if Wawrinka continues to serve solidly.
This summer period will be a busy one for Wawrinka as he will be representing Switzerland at the Olympics hoping to bring home a medal for his nation, and since Federer's withdrawal from the tournament has occurred, he will no longer play in the doubles event or mixed doubles competition.
Anderson is not going to Rio due to the scheduling of his tournaments and since the Olympics are offering no points, he is prioritising tour events over going to Rio.
The former top ten player will be hoping to carry on his good form in Toronto and he wants to ensure that he will be seeded at the US Open next month as he has quarterfinal points to defend and avoiding the big names in the early rounds is key if he's seeded.
Wawrinka hasn't won a Grand Slam title so far this year but he will be hoping that he can add to his cabinet by winning the US Open next month and he may get his hands on a big trophy with Federer missing and Nadal, not at 100%.
This is the first quarterfinal match of the day at the Aviva Centre in Toronto at 12:30pm local time on Centre Court and the winner of this match will face third seed Kei Nishikori or Grigor Dimitrov, who is looking to rediscover some form in the semifinals.
Prediction: Wawrinka in straight sets