SHANGHAI, China (AP) – Andre Agassi lost to Nikolay Davydenko, then pulled out of the Tennis Masters Cup less than an hour after second-ranked Rafael Nadal withdrew with an injured left foot.

Nadal withdrew Monday while Agassi was on court, losing 6-4, 6-2. The 19-year-old Spaniard had been due to face Gaston Gaudio in his opening round robin-match in the Gold Group.

Mariano Puerta became the fourth Argentine player in the draw when he was drafted to play compatriot Gaudio in Monday’s later match at Qi Zhong Stadium.

Fernando Gonzalez of Chile will take Agassi’s place in two remaining round-robin matches in the depleted Gold Group.

Top-ranked Roger Federer, also on the comeback from injury, leads the Red Group. He overcame Argentine David Nalbandian in his opening match Sunday.

Argentine Guillermo Coria and Ivan Ljubicic are in Federer’s group.

Agassi lasted 1 hour, 14 minutes against Davydenko, then said he couldn’t play the rest of his round-robin matches because he aggravated an injury in his left ankle.

“No chance for me to play again – it’s very dangerous and risky for my future,” Agassi said.

“This is an unfortunate setback.”

Nadal said he had consulted local doctors in Shanghai and the tournament doctor, and all recommended he withdraw and rest the damaged ligaments in his foot.

Nadal said he hadn’t been able to play or train since hurting the foot in his win over Ljubicic last month in Madrid.

The two latest injuries are a major setback for the season-ending Masters Cup, which is supposed to feature the top eight players of the year.

No. 3 Andy Roddick and Australian Open winner Marat Safin withdrew before the tournament because of injuries. Lleyton Hewitt, ranked fourth, opted to remain in Sydney with his wife, actress Rebecca Cartwright, who is expecting the couple’s first child within two weeks.

Agassi was playing in his first tournament since losing the U.S. Open final to top-ranked Federer in September.

“When you haven’t played in so long – I couldn’t really hit balls for a couple of months because of my sprained ankle – you came back, try to get ready in a hurry and you force it and thing just don’t respond,” he said.

Agassi said the hardcourt surface was difficult for a comeback tournament.

“It’s very sticky. It stops and everything else moves. It’s hard to have confidence. Then when you try a little bit, it’s still painful,” he said. “Today was obviously taking a chance to test (the ankle) out – I was just getting worse. It’s not ready.”

The loss to Davydenko extended his run in Shanghai to 0-4, including two matches at the 2002 Tennis Masters Cup before he withdrew from that tournament and a first-round loss at a tournament here in 2001.

The 35-year-old American started the match with his regular hustle, losing only one point in his first three service games.

He had a break point chance in the sixth game but hit a forehand wide and Davydenko held for 3-3. Agassi led 40-15 in the next game before dropping serve when his 24-year-old Russian opponent produced three consecutive backhand winners.

Davydenko needed three set points before closing with a booming first serve.

Agassi started the second set aggressively, winning his first seven points on serve for a 2-1 lead before Davydenko went on a five-game roll.

AP-ES-11-14-05 0933EST