Andre Agassi’s tearful goodbye on Sunday is the moment everyone will remember, but the U.S. Open, and tennis, must go on. Here’s our take on the male contenders with the best (that is, not very good) chance to unseat defending champion Roger Federer as week two continues.

RAFAEL NADAL

The 20-year-old Spaniard easily defeated Jiri Novak yesterday, 6–1, 7–6(3), 6–4. He has a great draw, and says he is playing his best tennis of the summer, though not his best tennis. One concern is his right ankle. Nadal needed treatment for it yesterday, and said it continued to hurt him after his received a new wrap. Nadal missed several months with an inflamed tendon in his foot, beginning at the end of last year (he even feared that the injury might end his career). He previously suffered a stress fracture in the same area. A spokesman for the ATP Tour who is close to Nadal, Benito Perez-Barbadillo, said yesterday that the two injuries were not related. Nadal next faces Mikhail Youzhny, a surprise quarterfinalist who battered Tommy Robredo yesterday, 6–2, 6–0, 6–1.

JAMES BLAKE

Blake has struggled all summer; so far at the Open, he’s played patchy but won with relative ease. His next opponent, Tomas Berdych, is one of the most powerful hitters on the tour. Blake will have to be patient and not try to slug it out with Berdych ball after ball. If he survives, Federer is his reward.

MARAT SAFIN

Mr. Mercurial is playing well. So far. Check back tomorrow when he faces Tommy Haas, who survived five sets with American Robby Ginepri yesterday.

ANDY MURRAY

It was surprising to see Murray down Fernando Gonzalez in five sets over the weekend. The Scot’s smooth strokes and savvy are evident, though his fitness is such that one would never expect him to win a match of this intensity and length. Can he last, or will his body quit?

NIKOLAY DAVYDENKO

Murray’s next opponent will have much fresher legs. The Russian only played a set in the third round, and won his fourth round in four sets. He had a terrible start this summer, but won the title at the Pilot Pen in New Haven before the Open. One might recall the difficult time he gave Federer at the Australian Open this year.

ANDY RODDICK

Roddick had little trouble with the Benjamin Becker (6–3, 6–4, 6–3), the man who put the finishing touches on Agassi’s retirement. There’s a lot to like about Roddick’s play so far. He’s approaching the net more, and most important, serving remarkably well. His first-serve percentage has been above 70% in three of his four matches, and he has 64 aces. His draw should, help, too: the winner of Lleyton Hewitt and Richard Gasquet will prove a difficult quarterfinal, but considering Hewitt’s knee troubles and Gasquet’s bouts with inconsistency, things could be worse.

It must be said, however, that pronouncements regarding Roddick’s aggressive play have been overstated (he said a strong wind kept him at the baseline yesterday). In baseline rallies, he still retreats more than he charges; witness his five-set win over Fernando Verdasco, who pushed Roddick around in almost every rally. Roddick has just 24 forehand winners in five matches (that’s fewer than two a set) and three — yes, three — backhand winners.

If Nadal is at his best in a possible semifinal, Roddick will not get away with such timid play. “I still feel like I was playing better in Cincinnati,” Roddick said yesterday, referring to his only title of the year.