"It was just a rough matchup, he forced me out of my comfort zone consistently" - Andy Roddick on why Roger Federer was the 'biggest obstacle' he had to overcome

Andy Roddick could have been a five-time Grand Slam champion if not for the one and only Roger Federer, who has an unbeaten record against the American in Grand Slam finals in four meetings. The former World No. 1 attributes his poor results against the Swiss to nothing more than their natural differences in playstyle, which made their match-up particularly hard for him.

Overall, Federer has an unbelievable 21-3 lead in the head-to-head against Roddick (8-0 in Grand Slams). Speaking in a recent interview with the New York Post, the American gave his thoughts on why that was the case, lamenting how all his natural strengths were counteracted by the 20-time Grand Slam champion's own innate abilities.

The former US Open champion remarked that it was, in a way, similar to the match-up between Federer and Nadal, which was particularly hard on the Swiss because of Nadal's left-handedness and topspin. Just like how the Mallorcan can consistently push the Swiss out of his comfort zone, Federer's style of play had the same effect on Roddick.

"It was just a rough matchup," Roddick said. "There wasn’t much that I did well naturally that he couldn’t counter naturally. Even against Rafa [Nadal], I knew my first serve would bother him. I knew that I had a little bit more power through the court. And similarly to Roger [Federer] and Rafa, that matchup is more difficult on Roger because of the lefty and the spins. Roger forced me out of my comfort zone consistently."

The 39-year-old touched on one of those Slam finals losses -- at the 2006 US Open. Despite the end result, Roddick was happy with his performance during the tournament, since it came just after he had started working with Jimmy Connors.

"[The 2006 US Open] was fun ’cause I just started working with Jimmy Connors. And so there was a bit of hype around that partnership," Roddick said. "I had played pretty bad throughout that year except I kinda caught a little bit of form in the tournament in Cincinnati which is the biggest lead-in tournament and won that, and it kinda turned my entire year around."

The American had plenty of praise for Connors, especially for the valuable advice he gave him on how to use the New York crowd to his advantage. In fact, Roddick is of the opinion that no other player can compare to Connors when it comes to swaying the crowd's energy to throw off their opponents.

"I was really happy and relieved to play well there, obviously lost to Roger [Federer] in the final," Roddick said. "But I really enjoyed working with Jimmy and getting his advice on how to use the New York crowd. I don’t know that there was anyone ever better at that than him."

"That’s the match that I get asked most about; the only thing that I would really change is the result, and winning two more points one of five times" - Andy Roddick on his 2009 Wimbledon final against Roger Federer

Andy Roddick lost to Roger Federer in an incredible five-setter at the 2009 Wimbledon final

The most popular clash involving Roger Federer and Andy Roddick came at the 2009 Wimbledon final without a doubt, where the Swiss prevailed in an extraordinary five-setter that lasted well over four hours.

Having not lost his serve all match, the American had his serve and heart broken unexpectedly in the deciding set to hand the former World No. 1 a 5-7, 7-6(6), 7-6(5), 3-6, 16-14 win, a scoreline that also made it the longest men's singles Slam final in terms of games played.

Referring to the clash as his "Starbucks" moment, meaning that it was a match even strangers asked him about when they encountered him in public, Roddick remarked that he would change nothing about it except for the final result.

"That’s the match that I get asked most about. I say everyone has that Starbucks moment in their athletic career, and that’s the Starbucks moment where you see a stranger, they ask you about it," Roddick said. "The only thing that I would really change is the result, and winning two more points one of five times."

Other than that, the former US Open champion had no regrets about the way he went about the clash, executing his game plans at the highest level for the entirety of the match. As much as he regretted not winning two more points to close out the win, the former World No. 1 doesn't, even for a minute, doubt the fact that he gave his very best against Federer that day.

"But as far as having a game plan, executing it at the highest level in the biggest moment, I felt like I did that over the course of 4 ¹/₂ hours," Roddick said. "One of my coaches Jimmy Connors had a saying: “Operation successful, but sometimes the patient dies.” And that’s the way it felt that day. I felt like I did as much as I could, save for winning two more points."