Roger Federer (SUI)  vs. Marin Cilic (CRO) 
Kei Nishikori (JPN) . Sadly, the mouthwatering reprise of the 2014 US Open final ended up being a bust when a clearly injured Nishikori was only able to put up token resistance and gave up before completing two sets. So, this gives us a reprise of the 2014 US Open semifinal, which is the last time these two met in competition, and the result was Cilic basically blasting Federer off the court. Can he do so again? Possibly. But Center Court Wimbledon is very different from Arthur Ashe stadium. Federer has always handled big servers well, but Cilic also moves exceedingly well for a 6-foot-6 man. However, I have to believe that Federer has planned all year for just this moment, and will be properly prepared to optimize his chances of winning this match (and the next two). That being said, I seriously doubt this will be a straight sets win (in either direction), and I do worry about the impact of a long, physical affair on Federer's chances. However, there's a reason he has reached 14 quarterfinals and 10 finals (and semifinals) at this tournament in his career. I think he will reach #11 this year. PREDICTION: Federer.
Andy Murray (GBR)  vs.
Richard Gasquet (FRA)  Jo-Wilfried Tsonga (FRA) . Tsonga is very lucky to be in this position. He was down 2 sets to none against John Isner in the 3rd round late on Saturday when he won a 3rd set tiebreak and eventually was able to even up the match by winning the fourth. He was serving second in the fifth set so eventually every breakpoint became a match point and yet he was able to save them and eventually broke Isner's serve and successfully served it out to win the fifth set by the ridiculous score of 19-17. Then his countryman Richard Gasquet gave him a gift by retiring after playing a mere six games to allow him to reach another quarterfinal here at the All-England Club. Unfortunately, he is playing someone whom he has a 2-12 head-to-head record against, and has really only been able to beat when playing his very best tennis (i.e. 2008 Australian Open and 2014 Rogers Cup in Montreal) and it is very unlikely that will not be the case on Wednesday. In fact, I would be very surprised if Murray lost a set, but I suspect atleast two of the sets will be very tight, single service-break or tiebreak affairs. PREDICTION: Murray.