KEY BISCAYNE, Fla. (AP) Rafael Nadal says his return to the Miami Open brings back mostly good memories, even though he's 0-4 in finals.
Nadal enters the event for the 11th time Saturday, when he plays his opening match against Damir Dzumhur. The 14-time Grand Slam champion is seeded only fifth and hasn't claimed a title since August. But he has won 35 matches at Key Biscayne and is liable to hang around until next weekend, which would delight South Florida's many Spanish-speaking fans.
''I think I played well in my career here, no?'' Nadal said Friday. ''It's a positive tournament for me. Only negative thing is I finally never win it. But the feeling, the atmosphere here is great. I enjoy being here. The fans here are amazing with me, so just enjoy.''
Another fan favorite, five-time champion Novak Djokovic, won his opening match by beating Kyle Edmund 6-3, 6-3. Djokovic improved to 23-1 this year.
Roger Federer was forced to postpone his return from knee surgery because of a stomach virus. He was scheduled to play Friday for the first time in nearly two months, but he withdrew shortly before the match because of the illness.
''I feel bad for the tournament and the fans, as I have rarely ever had to withdraw at such short notice,'' Federer said in a statement. ''I have not felt great for a few days, and unfortunately it got worse in the last 24 hours.''
Federer has been sidelined since undergoing arthroscopic surgery Feb. 3 for torn cartilage in his left knee. The 2005-06 Key Biscayne champion hasn't played in the tournament since 2014.
''It's obvious that a tournament with Roger is always better,'' Nadal said. ''It's good that it's a stomach problem and at the same time it is not the knee, so it's not a big deal. But it's obvious that it's terrible news for the tournament.''
Federer's return will now likely be on clay next month at Monte Carlo. He was replaced in the Key Biscayne draw by lucky loser Horacio Zeballos, who defeated Juan Martin del Potro 6-4, 6-4.
American 18-year-old Taylor Fritz held two set points in the opening set but lost to No. 8-seeded David Ferrer 7-6 (6), 6-1.
In women's play, No. 10 Venus Williams lost her serve nine times and was beaten by qualifier Elena Vesnina 6-0, 6-7 (5), 6-2. It was the earliest exit ever for Williams in 17 appearances at Key Biscayne, but she took the loss well.
''I always enjoy my time on the court,'' she said. ''I have a blast every single tournament, whether I win or lose.''
Williams won the title in 1998, 1999 and 2001.
Nadal was the Key Biscayne runner-up to Federer in 2005, Nikolay Davydenko in 2008 and Djokovic in 2011 and 2014. Last year he reached only the third round and complained about a crisis of confidence, and subsequent results reflected his doubts.
Nadal's 39-match French Open winning streak ended with a quarterfinal loss to Djokovic, and he was eliminated in the second round at Wimbledon and the third round at the U.S. Open.
This year he lost to Fernandez Verdasco in the first round at the Australian Open, and to Djokovic in last week's semifinals at Indian Wells. He has battled troublesome knees for years, and perhaps the grind of the tour has taken an irreversible toll.
But Nadal said he's in a better place mentally than a year ago.
''I am enjoying the practices, I am enjoying the tennis court,'' he said. ''I feel with the right energy. I can lose, I can win, but I am happy on court.''
His favorite part of the year looms - clay-court season. So does his 30th birthday, but Nadal doesn't sound as though he's nearing retirement.
''I enjoy playing my sport,'' he said. ''It's about love for the game, about passion for what I am doing, and I am going to be here until I am unhappy doing what I am doing.''