Brazilian striker Ronaldo admitted he has been hurt physically and mentally by his last injury and that he will have to think twice before coming back to action. "My heart tells me to play again but my body is sending me signs of fatigue and suffering," said Ronaldo while he was leaving the hospital after undergoing a knee surgery. "It has been a real knock-out blow, both physically and mentally," he admitted. "I still don't know how it happened. I still mustn't think about playing again. I must focus for the moment on undergoing the best physio possible. This will be very tough," added the AC Milan forward. "If I'm okay at the end of that, then of course I'll play again. If there's another ending, it will be a difficult and sad decision. I know exactly the bridges I have to cross. I have experience of recuperating from injury." The 31-year old marksman said he had a successful career and is quite satisfied with what he has done. El Fenomeno has hinted that it would be tough to be back and regain his form especially that he will be out for nine months and by that time he will be 32.