As the tours gather again for the first time since the Australian Open, here are five things to watch on the men's side when the BNP Paribas Open begins in Indian Wells, Calif.:
The Australian Open trophy ceremony showed once again that Roger Federer isn't one to mask his emotions. His teary reaction to losing the final in Melbourne created mixed responses, but there was little insight into how Federer felt until a recent interview with Swiss TV show "Glanz and Gloria."
"Embarrassing" was how Federer described his breakdown, saying that tears were fine after a win but not after a loss. But the outpouring did have one positive, he added, allowing him to get out the worst of his emotions immediately.
"Once I'm at the hotel, I think, 'Too bad it didn't work out. Anyway, my career isn't over yet,'" Federer said. "I've already achieved so much that I don't have a problem accepting when it does not work out at times. I'm happy for Nadal when he plays so well."
Arriving at Indian Wells, Federer will be relieved that the news cycle has moved on and the buzz will now be all about new coach Darren "Killer" Cahill.
The play of the dethroned No. 1 will be eagerly scrutinized to see what impact Cahill has managed to have during their short time training together in Dubai. But when it comes to the question of how the Australian Open loss affected Federer psychologically, his expressive face may offer more clues than his strokes.
His pale, withdrawn countenance this time last year coincided with some patchy post-mono performances, while a relaxed, smiling demeanor at the U.S. Open heralded a turnaround in fortunes. With the prospect of another hard-court final against Nadal looming, how jolly will Roger be at Indian Wells?
Andy Murray spent the offseason on an intense training regimen and a 6,000-calorie diet, but a large chunk of that investment has been wiped out by the virus which struck him in Australia and resurfaced in Dubai two weeks ago.
Following his pullout in Dubai, Murray announced that he would also have to miss the Davis Cup after being told by doctors to rest for at least a week. "This virus has hit me harder than any illness I've had before and I still feel terrible," he explained.
Yet another instance of mono? That has not been confirmed, but either way, it could take the 21-year-old some time to get back on track if his conditioning has been significantly affected. After all, he credits most of his dramatic improvement last summer to increased fitness.
Murray was huffing and puffing toward the end of his five-set loss against Fernando Verdasco at the Australian Open and felt "cold and sort of shivery" during his second-round match in Dubai. Yet he did manage to win the title in Rotterdam in between -- defeating Nadal along the way.
Murray's energy level between points at Indian Wells will signal whether he's currently feeling the aftereffects of the virus. But stare closely: The Scot looks pale and lethargic even under normal circumstances, and it can be difficult to tell the difference.
The world No. 1 comes into Indian Wells inspiring nothing but awe. A knee-related injury affected Nadal in Rotterdam and kept him out of Dubai, but he put on an intimidating display against Serbia in Davis Cup play last weekend.
There were some signs of rust in his opening match against Janko Tipsarevic, but he dropped only three games and then thoroughly dominated Novak Djokovic in the reverse singles. A frustrated Djokovic even pulled down his shorts after the Spaniard saved a break point in the third set with a lucky net cord.
But Nadal must now make a quick shift from the powdery clay court in Benidorm to the hard courts of Indian Wells and then Miami. His oft-injured knees and feet are always a bit vulnerable during a long stretch of hard-court play, and injury has stopped him more often than any opponent this year.
Not literally, perhaps, but Djokovic is constantly watching his back these days for encroaching rivals. At the Australian Open, he was told that Murray had displaced him as the "third man" in men's tennis. Now there's talk about whether Andy Roddick has also moved ahead after a solid start to the year.
Djokovic provided a strong rebuttal by winning the title in Dubai but lost some momentum after a lackluster Davis Cup weekend. "I went for my shots and I've got back my confidence from my Dubai win," Djokovic said to console himself after his loss to Nadal.
So as Indian Wells gets under way, the Serb is under pressure to defend not only his title, but the continued concept of a "Big Four" in men's tennis. A rematch with Roddick following their quarterfinal encounters at the U.S. Open and Australian Open would be intriguing indeed.
Davis Cup hangovers
Then there are some -- Nadal, Roddick, Radek Stepanek, Marin Cilic -- coming in on a high after taking their Davis Cup teams to victory. Others -- Djokovic, Gilles Simon, Jo-Wilfried Tsonga -- saw their teams suffer dispiriting losses. They'll all have to adjust quickly to shake off the hangover.
Kamakshi Tandon is a freelance tennis writer for ESPN.com.