NEW YORK • Rafael Nadal may have erased any lingering concerns over an injured left wrist and made a powerful start to the year's final Grand Slam, but the Spaniard is uncertain what the second week of the US Open holds for him.
It is the first time the 30-year-old is heading into the second week at Flushing Meadows since his second title run in 2013.
The fourth seed looked in fine form in a 6-1, 6-4, 6-2 victory over Russian Andrey Kuznetsov on Friday.
But with the memory of his forced retirement from the French Open with a wrist injury that also caused him to miss Wimbledon still fresh, Nadal is taking nothing for granted.
"I don't know in which kind of level I am," said Nadal, who won titles in Monte Carlo and Barcelona before his season was interrupted.
"It's true that, when I had to stop, I was playing great.
"I felt myself ready for the French. I don't know where I am today. Only thing I know is I am happy.
"I am excited to play the US Open. For me it's great news that I am on the Tour again, and I am playing every day with less pain on the wrist. That's the most important thing."
Nadal was all but flawless in the opening set on Friday, but wilted a little as Kuznetsov stepped up the attack in the second.
"I lost the serve in the second for a couple of games. I was serving badly," he said.
"When you play against a player like him that's able to return quick, hit a lot of good shots, then you are in big trouble. That's what happened."
With the second set secured, a relaxed Nadal got back in the groove, although a double-fault sandwiched between two forehand errors saw him waste three match points in the final game.
He gave himself another chance on the next point when he kept an entertaining rally alive with a between-the-legs lob, and finished it off with a service winner.
Nadal, who has not dropped a set in three matches, today faces France's 24th-seeded Lucas Pouille, a 3-6, 7-5, 2-6, 7-5, 6-1 winner over Spain's 15th-seeded Roberto Bautista Agut.
Although his quarter of the draw has opened up with the early exit of Wimbledon finalist Milos Raonic, Nadal said any player he encounters from here on will pose a serious threat, regardless of ranking.
Of his own world No. 5 ranking, he said: "Sometimes I can play better than the No. 5, sometimes I can play much worse than the No. 5.
"And that happens the same with the other seeded players," he added.
"We'll see what's coming the next couple of days."