Reflecting on Rafa's Week 1 results

MELBOURNE, Australia -- Four matches down, three to go for Rafael Nadal to complete the "Rafa Slam." Nadal beat 2010 semifinalist Marin Cilic on a chilly Monday night to move into the quarterfinals at the Australian Open.

It hasn't been all smooth sailing for Nadal, however.

Here are a few observations from his first week.

He's not 100 percent

At every tournament, players are banged up, including at the start of a season. Nadal entered the Australian Open sapped of strength after falling ill during the Qatar Open, delaying his arrival to Melbourne. Anyone who watched his loss to Nikolay Davydenko knows something was amiss.

As the Happy Slam began, Nadal said the virus was out of his system. But in the wake of downing Aussie upstart Bernard Tomic on Saturday, he admitted he still felt tired during practice.

That was pretty obvious, too. As early as the second game, he was huffing and puffing, and sweating profusely. Nadal went through countless shirts on a warm, but not stifling, night. He told Spanish reporters he'd lost five pounds in the match.

There's always the possibility of Nadal getting better, of course. He claimed in an on-court interview after the Cilic match that he felt a lot better and didn't have a problem with sweating.

All told, if he's to win here, he'll have to do it at less than full strength. These things happen, as Roger Federer can attest to, and Nadal has to deal with it.

He hasn't lost a set, which is good news.

"I was able to play with high intensity, very good rhythm, playing more inside the court," Nadal told reporters Monday. "So play more aggressive, changing rhythms with the slice and with the topspin, backhand. I think it was a very good match for me and very important victory."

The serve is a little off

If lacking a little energy, the serve is predictably bound to suffer. The numbers show Nadal's delivery hasn't been as rapid as it was at the U.S. Open. It's no stretch to say Nadal's serve went a long way toward helping him finally conquer the Big Apple.

Through four matches at Flushing Meadows in 2010, Nadal routinely hit 130 miles per hour. He's having a hard time topping 125 mph in Melbourne. Versus Tomic, the average speed was significantly lower.

His ace count in New York was 30 through four rounds; in Melbourne it's 18. Even Nadal needs cheap points once in a while.

Nadal, on a positive note, hit two big serves from 5-4, 30-40 in the second set against Cilic to get out of danger.

"The serve worked better today," Nadal said.

Moving forward is key

Following his scare against Tomic -- well, he trailed 4-0 in the second set -- Nadal said he was too passive. He lingered behind the baseline against the 18-year-old for a while before making an adjustment, moving forward. Two net approaches in the first set were followed by a combined 20 in the next two.

Indeed, Nadal's good hands and volleying skills mean he shouldn't hesitate if getting a chance to put away balls at the net. We don't necessarily mean serving and volleying, but following up those heavy groundies.

Nadal was successful on 16 of 17 approaches versus Cilic.

Feeling a bit tight

Nadal usually handles pressure flawlessly. Just look at how he deals with break points.

But on the verge of becoming the first man in 42 years to win four straight majors, could he be feeling it a little?

Nadal admitted after the Tomic match that he sweats more when feeling anxious.

And let's not forget that on the eve of the tournament, he said he wasn't the favorite. Rather, he put himself behind Federer and in the same class as Novak Djokovic, Andy Murray and Robin Soderling. That was funny.

Nadal should ease past fellow Spaniard David Ferrer in the quarterfinals Wednesday. Then the competition goes up a notch.

Ravi Ubha is a frequent contributor to ESPN.com.