MILAN, Italy — AC Milan striker Ronaldo wants to attempt a comeback once his left knee recuperates from what some experts said would be a career-ending injury.

"For now it's still early to speak about decisions, but I'm preparing myself for the great challenge of returning to play," Ronaldo said today in comments published on the team's Web site.

The three-time FIFA world player of the year ruptured a tendon in his left knee last month while playing in a Serie A match. He had a successful operation and immediately began physical therapy. Doctors say the earliest he could play again would be in about eight months.

The 31-year-old Brazilian is the leading scorer in World Cup history with 15 goals.

Ronaldo has battled serious injuries throughout his career, including a right knee injury when playing for crosstown rival Inter Milan eight years ago. He missed the following season, but came back strongly at the 2002 World Cup, guiding Brazil to its fifth title with eight goals, including both in the final against Germany.

Ronaldo's contract with Milan expires at the end of June.