The Brazilian sensation played down injury fears after going off with a cramp in the Serie A 3-1 victory over Chievo on Saturday.

“I knew that slowly I would rediscover my form. Physical fitness is the most important thing and I hope to be at the top of my game for the derby,” Ronaldo told Calcio Italia magazine on Sunday.

The 30-year-old striker said that he is looking forward to Sunday’s game, noting that he has sufficient time to prepare.

“I cannot play in the Champions League, so I have a whole week to train before the big match. I aim to take full advantage of that opportunity,” he said.

Ronaldo had played for Inter between 1997 and 2002 before moving to Real Madrid and finally returning to Milan to feature for the Rossoneri in January.

Ronaldo produced a fine performance in the Chievo match, setting up Massimo Oddo for the winner.

“It was a good performance and all I was missing was a goal.

“I’d like to score in every game, but I know that won’t be possible. Actually, I was told that the goal I had disallowed in the first half for offside was valid, but these things happen,” added the Brazilian.

Milan will face Celtic in the Champions League last 16 second leg at the San Siro on Wednesday but the former Real Madrid forward is ineligible for the tie, whose first leg ended in a goalless draw.