"The aggression will come, him opening up the shoulders and bullying people will come" - Andy Roddick on Rafael Nadal's comeback

Andy Roddick believes Rafael Nadal's peak tennis is not too far away, despite the Spaniard only just making his comeback at the Madrid Open.

Nadal spent more than a month on the sidelines after fracturing his rib at the Indian Wells Masters in March. He returned to competitive action in Madrid on Wednesday, beating Miomir Kecmanovic 6-1, 7-6(4).

In a conversation for Tennis Channel, Roddick was asked to rate the Mallorcan's performance out of 10. The American went with six but was quick to point out that one need not worry about Nadal on clay.

"Yeah, I mean probably about 6, he looks like a guy that hasn't played a tournament in a while but you don't really worry about him on the clay," Andy Roddick said.

Roddick explained that Nadal does not take much time to find his game and that his basic style of play is already in good shape. The former World No. 1 suggested that the 21-time Major champion will seek to eliminate unforced errors from his game before fine-tuning his attack.

"One of Rafa's big things is he can get into these matches and the aggression will come, him opening up the shoulders and bullying people will come," Roddick added. "His base level of 'listen I can run, I can grind, I can put the ball in awkward spots for my opponent up above their shoulders' that really never goes away."

"He's gonna keep his unforced error-level low - that's a nice backup plan to have before everything starts making sense in the offensive side of all."

"What he went through when he went into the Australian circuit has given him confidence here in Madrid" - Pam Shriver on Rafael Nadal

Pam Shriver also gave her two cents on Nadal's comeback. She highlighted that the Spaniard did well on the clay in Madrid, which has historically been a tough tournament for him due to its altitude.

Shriver also alluded to the 35-year-old's comeback earlier this year when he returned after nearly five months to lift the Australian Open title. Shriver feels Nadal must have drawn confidence from his run in Melbourne.

"I love also he says "I manage it very well" - no kidding, no kidding, we've seen him manage it well for 18 years," Pam Shriver said. "By the way this is the tournament that is like terrible for him in consideration to other claycourt events. He's used to coming back now, the last six months from an injury. I think the fact what he went through when he went into the Australian circuit has given him confidence here in Madrid."

Nadal will face David Goffin in the last 16 of the Madrid Open on Thursday.