Manchester United star Cristiano Ronaldo is reportedly an injury doubt for the new coach after injuring his knee while celebrating a goal on Thursday.

Read: Ronaldo Sends Message To New Coach After Carrick's Sudden Exit

The Portuguese forward bagged a brace as the Red Devils defeated rivals Arsenal 3-2 to get their Premier League campaign back on track.

However, Ronlado was taken off shortly after scoring United's third goal from the penalty spot and he was seen walking down straight down the tunnel.

The Sun have now reported that Ronaldo may have injured his knee doing his trademark celebration and is now a doubt for Sunday's clash against Crystal Palace at Old Trafford.

It remains to be seen if Ronaldo will be available for selection on Sunday afternoon, but interim manager Ralf Rangnick revealed earlier this week that he has to make sure all the players have enough energy for the clash.

“I cannot do a lot with the players that played against Arsenal because I need to make sure that they have enough power and fuel in the tanks for the game on Sunday, so physically we cannot really train.

“So, the only way to help them and to give them an input is mentally obviously, with regard to energy.

"Against Arsenal the second half showed that there is enough energy in the team.

“Of course it's about video footage, showing them the right situations, telling them what they might be able to do better to keep the team away from their own box - those kinds of things.”

Here are 10 other stars who have copied Ronaldo's trademark celebration: