Andre Agassi [Images] made a confident start to his season when he beat Brazilian Ricardo Mello 6-4, 6-4 in the first round of the Delray Beach International Tennis Championships (ITC) on Monday.

The 35-year-old top seed, who missed this month's Australian Open due to an ankle injury, served 10 aces and needed just 67 minutes to see off Mello, the 2004 Delray Beach champion.

"It felt good, it was pain free," Agassi told a news conference, when asked about the ankle. "I've just got to run faster now, that's all."

The eight-times Grand Slam champion, who lost to world number one Roger Federer [Images] in last year's US Open final, said he had felt "random moments of frustration" about his shot selection and a lack of sharpness after an extended period of inactivity.

He laughed off a question about whether he would retire at the end of the season, which would end a 21-year career for the Las Vegas [Images] native who turns 36 in April.

"Yeah, I don't know. I suppose every year I'm getting closer to it, right? If I come up with any plans I'll call you," he said.

Agassi, who had not played since pulling out of a Masters Cup match against Nikolay Davydenko in November, hinted that time is not really on his side.

"I think as you get older you appreciate things more," he said. "You realise that they'll be over soon."

• Complete tennis coverage
• All you want to know about Sania Mirza