Novak Djokovic's power of recovery

MELBOURNE, Australia -- The big question about Novak Djokovic coming into the Australian Open was whether anyone except Andy Murray or Roger Federer could possibly challenge him. Since that has happened, now the question is how the world No. 1 will react.

First, there's the physical aftermath to his epic five-hour, five-set match against Stanislas Wawrinka in the fourth round. Djokovic was clearly exhausted by the end of the 12-10 fifth set and also appeared to be having physical problems. "But still, I've been in those situations before," Djokovic said afterward, pointing to his performance in the last two rounds of last year's Australian Open.

"I won against Murray in the semis after five hours, and then played against [Rafael Nadal] almost six hours.

''I know I can recover. I know I have it in me."

So even though there are still three rounds left to go this time, no one left in the draw will be underestimating Djokovic's power of recovery. The possibility of an injury lingers, though Djokovic's coach, Marian Vajda, said after the match he suspected the problem was only back spasms, which could be "released" by rest and massage.

Either way, there is now blood in the water, and he will have to turn up the intensity against the rest of his suddenly opportunistic opposition.

Psychologically, however, Vadja felt the close shave would spur Djokovic. He said the world No. 1 had been surprised by Wawrinka's stellar start and had taken a while to adjust his own game. "But obviously Novak now realize it's not [an] easy way to go to the final and he realize he has to be better in the next match," said Vajda.

Djokovic also feels that surviving this test will give him a boost the rest of the way. "These kind of matches, after five hours, definitely help your confidence," he said.

History is also on Djokovic's side. Three other times, including his win last year, a player has played longer than five hours and gone on to win the tournament.

His next opponent, Tomas Berdych, is in the opposite situation -- well rested but not as mentally strong. "I felt pretty good. I mean, I just play every single match by three sets," said Berdych after his fourth-round victory. "Everything was fine. I felt physically well."

The Czech possesses a huge game and has scored multiple wins (and near-wins) over contemporary greats like Federer and Nadal, but has had a reputation for choking for much of his career. But he has matured and toughened up over the past couple of years. Berdych insists that last year's missed volley for a two-set lead over Nadal in the quarterfinals was a harder shot than it looked. And he is feeling the afterglow of the Czech Davis Cup victory at the end of last season.

Despite coming into the tournament a little unsure of his form, Berdych has found his game and stands poised to take advantage if Djokovic shows up weakened for their encounter.

Even though Berdych is on the wrong end of a 11-1 record against the Serb, they are 1-1 in Grand Slam matches. Berdych beat him in the 2010 Wimbledon quarterfinals, when Djokovic was returning to form after a long slump, and Djokovic returned the favor by beating him in the 2011 Australian Open quarterfinals.

Berdych joked in his postmatch interview that he hoped his third quarterfinal would be third time lucky, and then cracked another joke in his news conference about the 15-13 tiebreaker that ended his fourth-set match. "So far this year I didn't play any tiebreak, and this was the first one," he said. "I want to maybe enjoy that and stay there longer."

Tomas Berdych, comedian? That's new. Let's see if he can produce something equally unexpected when he takes on Djokovic.

Prediction: Berdych in five sets.

David Ferrer (ESP) [4] versus Nicolas Almagro (ESP) [10]

Nicolas Almagro might be David Ferrer's favorite opponent. A dubious distinction, since Ferrer has beaten him more often than any other player on tour -- 10 times in all, with no losses. That history will make it tough for the lower-ranked Spaniard, but he has the bigger game and nothing to lose so he'll be able to swing out freely and go for his shots. Even then, though, it's tough to beat the steady Ferrer that way in a best-of-five encounter.

Prediction: Ferrer in four sets.

Li Na (CHN) [6] versus Agnieszka Radwanska (POL) [4]

This is a fascinating faceoff between power offense and varied defense. Their previous meetings aren't that suggestive. Li leads 4-3 and won three of their four meetings last year, but Radwanska beat her in Sydney last week and will be going for her 14th win a row. The Pole is in better form, but Li will be the one dictating play and the match will turn on her performance.

Prediction: Radwanska in three sets.

Ekaterina Makarova (RUS) [19] versus Maria Sharapova (RUS) [2]

Sharapova has dropped only five games in getting to the quarterfinals, among the fewest on record. She also holds a 4-0 record against her compatriot, including a victory at this event last year. But Makarova's also been in good form, beating two seeds, and should give Sharapova her toughest test of the tournament so far. Not that that's saying much: A 6-4 set would do it.

Prediction: Sharapova in three sets.