NEW YORK, September 7 – Rafael Nadal's bid to complete a career Grand Slam hit a potential snag Sunday when a right abdominal muscle injury brought new health concerns even as the Spaniard reached the last 16 at the US Open.Third seed Nadal received treatment from a trainer in the third set of a 7-5, 6-4, 6-4 victory over 32nd-ranked countryman Nicolas Almagro and his reluctance to speak about it after the match added more fitness worries.
"I don’t want to talk about injuries," Nadal said. "I try my best every day. I won the match in three sets."
Pressed on whether or not the treatment helped him in the third set, the six-time Grand Slam winner replied, "I won 6-4. You can see I didn’t serve very fast but I think I played better from the baseline than before."
British second seed Andy Murray, last year’s US Open runner-up, defeated US 195th-ranked US wildcard Taylor Dent 6-3, 6-2, 6-2 in the feature night match at Arthur Ashe Stadium.
"I love playing night matches," Murray said. "The atmosphere was great. Obviously the crowd wanted Taylor to win but I played very well."
The 22-year-old Scotsman, trying to become the first British man to win a Slam title since Fred Perry in 1936, will play for a quarter-final spot against Croatian 16th seed Marin Cilic, who beat Uzbek Denis Istomin 6-1, 6-4, 6-3.
"He’s got a big serve and moves well for his height," Murray said of Cilic. "I’ll need to return well and I’ll have to be very solid from the back."
Nadal, whose best US Open run came into last year’s semi-finals, will play for a quarter-final berth against French 13th seed Gael Monfils, who was ahead 6-3, 6-4, 1-0 when Argentina’s Jose Acasuso retired with left knee pain.
"I have to come out ready for the next match," Nadal said. "For today it was enough but for sure I can do better."
Nadal called the trainer after breaking to pull within 2-1 in the third set.
After laying on his back on the concrete for treatment of what could be a flare-up of a muscle strain suffered last month at Cincinnati, Nadal held serve, broke for a 3-2 edge and served out to win despite discomfort.
"I feel it a little bit now but I will try to recover in time for my next match," Nadal said moments after the final point.
Nadal, the reigning Australian Open champion, is coming off a two-month layoff due to knee tendinitis, a break that kept him from defending his 2008 Wimbledon crown.
"I just plan to keep on improving my tennis and keep playing this tournament because it’s special to me," Nadal said. "It’s special motivation when you try to come back and play your best as fast as possible."
Murray, who matched Novak Djokovic with a tour-best 56th season triumph, fired 39 winners and seven aces against only 13 unforced errors and overpowered Dent, back at the elite level after missing two years for major back surgery.
"I returned really well. That was probably the key to the match," Murray said. "I managed to finish the match off well at the end."
With Murray’s victory, a US Open record 14 of the top 16 seeds reached the fourth round, breaking the old mark from 1992. All 16 men’s top seeds had reached the third round, a Grand Slam first.
The only absentees in the round of 16 were US fifth seed Andy Roddick, who lost Saturday, and French ninth seed Gilles Simon, forced to retire with a sore right knee with Spaniard Juan Carlos Ferrero leading 1-6, 6-4, 7-6 (7/5), 1-0.
Ferrero, the 2003 French Open champion and 2003 US Open runner-up, won his first title in six years at Casablanca in April and will face Argentine sixth seed Juan Martin del Potro for a last-eight berth.
Del Potro lost six games in a row at one stage but fired 20 aces in beating Austrian Daniel Koellerer 6-1, 3-6, 6-3, 6-3.
No Frenchman has won a Grand Slam singles crown since Yannick Noah at the 1983 French Open, but seventh seed Jo-Wilfried Tsonga, last year’s Australian Open runner-up, and Monfils are still in the hunt to end the drought.
Tsonga ousted compatriot Julien Benneteau 7-6 (7/4), 6-2, 6-4 to book a date with French Open semi-finalist and 2007 Australian Open runner-up Fernando Gonzalez, the Chilean 11th seed who beat Czech Tomas Berdych 7-5, 6-4, 6-4.
"(Tsonga) serves really big and he has strong shots," Gonzalez said. "We have to see who can make more winners."