Monday was the first time that Kei Nishikori or Marin Cilic appeared in a men's final, but it won't be the last for either player after their emergence at the 2014 U.S. Open.The two met in one of the unlikeliest Grand Slam finals matchups of the past decade, pegging the No. 14 Cilic against the 10th-seeded Nishikori. The lower seed ruled in the final, with Cilic brisking past Nishikori in a straight-set victory.But somehow, watching them play throughout these two weeks at Flushing Meadows proved that neither of them has the game of an underdog.Cilic, the 25-year-old Croatian, boasts one of the most powerful skill sets in the sport today. He uses a massive serve to his advantage, blasting aces past opponents and proving impossible to break throughout a match.While the powerful serve of Cilic is enough to dominate some opponents, he's unstoppable even for great players when he plays energized and attacks opponents' serves early on in the match.If you don't believe me, go ask Roger Federer or Tomas Berdych. They'll vouch.Nishikori won't be taking anyone by surprise either after his incredible run in New York. In fact, he should be getting talked about just as much as Cilic, despite the loss.The Japanese standout has impressed on the men's circuit for some time despite his ripe age of 24, but he had never put everything together prior to the U.S. Open. But after a four-set win over top-seeded Novak Djokovic along with five-set wins over Stan Wawrinka and Milos Raonic, he proved he's a force to be reckoned with in the men's game.There isn't a faster player from side to side right now than Nishikori, and he complements it with deceptive power on his forehand game. That makes him a force on break points when he's able to step into his returns.Obviously, he wasn't at his best on Monday against Cilic. But there's no doubting that the experience will be useful in the future:"For sure the experience will help," he said in the post-match interview. "You know, I was a little bit tight and nervous, you know, playing first final. But, you know, to get, you know, this experience gonna help for this season and next season, too."Nishikori won't soon forget the tough defeat, but his performance indicates that it won't be long before he's back in a similar position, perSports Illustrated Tennis:As for Cilic, it would be a surprise tonotsee him contending for Grand Slams throughout 2015 and beyond after his incredible few weeks in New York. Not only has he topped his competition, but he's crushed ithe didn't drop a single set in wins over Federer, Berdych and finally Nishikori.Cilic isn't an up-and-comer, having made the 2010 Australian Open semifinal, but there's a difference between emerging and staying there. With the way his game has flourished over the 2014 season, there's no doubt he has made that transition.Of course, Cilic and Nishikori aren't the only ones to make improbable runs to a Grand Slam final. But considering the improvements both showed in their respective games in New York, it won't be so improbable next time they make a final. Click here to read full news..