NEW YORK -- Rafael Nadal has no way of knowing how his aching stomach muscles will feel when he plays in the U.S. Open semifinals.
And no one else knows exactly how much Nadal is bothered by the injury, because he steadfastly refuses to delve into details on the subject.
What the six-time major champion is willing to make clear: He feels a lot less drained these days than he normally does by the time the year's last Grand Slam tournament -- the only one he hasn't won -- rolls around.
"I'm more fresh than last year, 100 percent sure. We will see how I am physically tomorrow. But mentally -- last year, [I] was totally destroyed mentally," Nadal said Saturday after finally completing his rain-interrupted quarterfinal win over an error-prone Fernando Gonzalez. "Mentally, this year, I am perfect, no?"
The No. 3-seeded Nadal beat No. 11 Gonzalez 7-6 (4), 7-6 (2), 6-0 in a match that began Thursday evening, was suspended that night because of showers in the second-set tiebreaker, and didn't resume until Saturday thanks to more rain Friday.
"I have to admit, I'm pleased that match is finished," tournament director Jim Curley said.
He joined U.S. Tennis Association executive director Gordon Smith at a news conference, where they declined to commit to building a retractable roof over Arthur Ashe Stadium, a topic of much discussion around these parts.
"It will be some time before there's any decision made on whether or not to go forward with the roof," Smith said.
Weather permitting -- two key words at Flushing Meadows lately -- Nadal will face No. 6 Juan Martin del Potro in one men's semifinal Sunday, and No. 1 Roger Federer will meet No. 4 Novak Djokovic in the other. The men's final, usually played on Sunday, has been pushed back to Monday on account of the weather for the second consecutive year, a financial hit for the U.S. Tennis Association. The men's final hadn't been played on Monday since 1987.
Gonzalez, for one, figures this year's championship matchup is a foregone conclusion.
"You always expect that Federer plays the finals against Nadal," Gonzalez said. "Good for the game. It's good for the fans."
Well, it is true that Federer and Nadal have met in seven Grand Slam finals already.
First things first, though.
Del Potro beat Nadal the last two times they played. Plus, the 6-foot-6 Argentine should be well-rested, considering that he hasn't played a point since his quarterfinal victory Thursday. Federer, seeking a sixth consecutive U.S. Open championship, and Djokovic, the 2007 runner-up, have been able to enjoy some R-&-R since winning their quarterfinals Wednesday.
Nadal? Not so much.
He and Gonzalez originally stepped on court Thursday at about 7 p.m. After Nadal won the first set, he took a medical timeout to have a trainer check his abdominal muscles. Then four games into the second set, there was a 75-minute rain delay. After play resumed, Nadal took a 3-2 lead in the second tiebreaker when they were forced off court for the night.
It wasn't until about 37 1/2 hours later that they picked up again. Nadal swept through four straight points -- all on miscues by Gonzalez -- to end the second set.
"So quick," Gonzalez said.
Things never got better for Gonzalez, who sought treatment from a trainer for his feet and simply kept missing the mark with his big forehand and less-imposing backhand, over and over and over.
Gonzalez wound up with 59 unforced errors in all, a read-that-again 46 more than Nadal.
"I can't tell you," Gonzalez said, "because I don't have the answer."
Nadal has been reluctant to answer questions about his health, saying Saturday that he will talk about it more once his U.S. Open is over.
After his stunning fourth-round exit at the French Open -- he was 31-0 at Roland Garros before that loss -- Nadal took time off to deal with tendinitis in his knees. He cited that as the reason for declining to defend his Wimbledon title, part of a two-month break he took.
While sidelined, he was disappointed to be away from the game. Now Nadal realizes it could be paying dividends, with less week-in, week-out, wear-and-tear on his body and mind heading to New York. Usually, the guy is exhausted by September.
When he returned to the tour in August, he did something to his stomach muscles, a problem that flared up again during his third-round victory over Nicolas Almagro last weekend.
Between that issue, and his knees, Nadal acknowledged having doubts about how well he would play at the U.S. Open, where he lost to Andy Murray in last year's semifinals.
"The doubts are now behind me," Nadal said Saturday. "I'm enjoying myself, and could do so more without the abdominal pain, which obviously complicates playing."