Manchester United winger Cristiano Ronaldo claims he is not given enough protection from referees.
The Portugal international, who has found the net 30 times in all competitions this season, believes he could suffer a serious injury due to a lack of protection from match officials.
The 22-year-old wideman claims he could suffer the same fate as Arsenal striker Eduardo da Silva, who faces 15 months on the sidelines with a badly broken leg and dislocated ankle following a mis-timed tackle.
Ronaldo was speaking after he was denied a first-half penalty during United's 1-0 FA Cup sixth round defeat to Portsmouth at Old Trafford on Saturday.
"It's very frustrating, the referee was unbelievable," he told MUTV about the performance of match official Martin Atkinson.
"He didn't want to give the penalty, he didn't want to give yellow cards. I'm very disappointed.
"Refs don't protect skilful players. I think about the Arsenal player (Eduardo) and I'm scared sometimes to do skills because some players do unbelievable fouls and the ref protects the defender, not the skilled player.
"It's very disappointing and I'm thinking a lot about changing my game. When referees don't give penalties, yellow cards or reds, it's difficult to play."