Noah Rubin is making his debut as a main draw player at the French Open in less than a week, and his jeans don't fit anymore.
Nothing to worry about -- the problem isn't in the waist. It's at Rubin's thighs, which have grown more muscular because the 22-year old former Wimbledon junior singles champion ramped up his workout regimen.
"I've always been fit, ready and able to run for a long time," Rubin told ESPN.com. "But now in tennis you have to be a gym rat. That's the biggest improvement in my game. I've worked on my strength, and I'm doing a much better job taking care of myself in general."
Rubin earned one of the two wild cards the French tennis federation gives the USTA in a reciprocal arrangement designed to reward young players. The women's wild card went to Taylor Townsend. She's something of a Roland Garros veteran, having won the same wild-card playoff way back in 2014 at the age of 18, after which she created a sensation in Paris by reaching the third round.
This will be Townsend's fourth French Open main draw appearance (her record is 3-3). But the experience won't be entirely new for Rubin, who won matches in the boys championships.
In 2013, as a 15-year-old, Rubin upset Liam Broady (then one of the world's top juniors) and reached the quarterfinals. The following year, he lost a tight three-set, third-round battle with Kyle Edmund.
"Before I won Wimbledon, clay was my best surface," Rubin said.
It's easy to understand why Rubin have put his clay game on the back burner after taking the boys' title at Wimbledon. But there was another reason his clay game fell into neglect, and that one isn't unique to Rubin. It has impacted generations of American players.
"I really enjoyed moving on the clay. I guess it was unusual, because I'm an American. But then I went to college," said Rubin, who played collegiate tennis during the 2014-15 season at Wake Forest. "When you go to college, the clay gets lost. It's all hard courts. I didn't play on clay for that entire year."
At the end of his stay at Wake, Rubin was injured, unable to vie for the USTA French Open wild card. The net result was limited clay-court experience and dedication to other priorities until this spring, when Rubin focused on the Futures and Challengers tournaments that comprised the wild-card playoffs. He needed only two events to lock up the wild card because he reached the finals of a Futures event and won the Tallahassee Challenger.
Rubin's success on clay also sprang from his willingness to come to grips with a reality that many other American players have found unpalatable.
"Whether you're playing (Rafael) Nadal or your grandmother, it's going to be a tough match," Rubin said. "You just have to accept that. You may think you can tear a guy apart on a hard court, but on clay suddenly you're three hours in, it's the third set, and you aren't done. That's what you have to get used to. Every match can be brutal. Expect it."
That attitude paid off for Rubin in Tallahassee, where the key to his win was a semifinal upset of clay-court expert Hugo Dellien. Rubin knew his opponent had been overpowering opponents but also playing a lot of tennis, so he resolved to make him work for every point.
"I wasn't going to give him any free points, and I was going to take advantage of any ball he left laying," Rubin said. "I think he knew it was going to take more out of him physically than he was willing or able to give that day to beat me. I think it's often like that that on clay."
Rubin left for Paris last week and entered the qualifying for the current ATP 250 in Geneva. He reached the main draw, where he upset former Australian Open finalist Marcos Baghdatis in the first round. He plays clay wizard Fabio Fognini on Wednesday.
The Long Island, New York, native has added incentive to collect prize money in the coming days as he will be joined in Paris by his girlfriend, Janie Weissler. A recent college graduate, she is going off to veterinary school in Minnesota while Rubin tries to improve on his present ranking of No. 204.
The couple has plenty to celebrate, which inevitably means enjoying French cuisine. It may be even harder to fit into those jeans after a few of those evenings out.