Manchester United have already begun the process with the Premier League to get special dispensation for Cristiano Ronaldo to wear the No.7 shirt.
Ronaldo made the number his own in his previous stint at Old Trafford after following in the footsteps of club greats Eric Cantona and David Beckham.
After briefly being handed the No.9 shirt at Real Madrid, he soon reverted to No.7 after the departure of club captain Raul, and also bore the same shirt at Juventus, as well as for Portugal.
But Premier League rules state in the handbook that players must wear the same shirt for the whole season - with United's No.7 currently in the possession of Edinson Cavani.
However, United are now working to try and get Ronaldo back in his preferred number, while they've also laid out a contingency plan should their request not be granted.
According to the MEN , should United's plea be rejected, Ronaldo will be handed the No.21 shirt instead.
The whole situation could be made easier if Cavani ends up leaving the club on transfer deadline day.
The Uruguayan forward only signed a one-year contract extension earlier this summer after weighing up his future for months.
Cavani was concerned he would not get regular minutes amid rumours United were in the market for a centre forward, but eventually committed to the club until next summer.
United's move for Ronaldo was not part of the club's plan, but his arrival will now have an impact on how often Cavani will get on the field.
As Ole Gunnar Solskjaer put it on Sunday regarding Ronaldo: "He's not come to sit on the bench."
That has put Cavani's future in sharp focus, with Barcelona now linked with a deadline day swoop to sign the 34-year-old.
Last minute talks are said to be taking place between both clubs, with RAC1 reporting that negotiations are at an advanced stage.
Cavani is also said to have agreed to the move, but United are still unsure whether to let him go at this time.
Should he depart, Ronaldo will be free to take the No.7 shirt for both Premier League and Champions League matches.
United confirmed Ronaldo's transfer had been completed in an announcement on their website, with the striker then posted a heartfelt message to the club's fans.
“Everyone who knows me, knows about my never ending love for Manchester United,” he wrote on Instagram. “The years I spent in this club were absolutely amazing and the path we’ve made together is written in gold letters in the history of this great and amazing institution.
“I can’t even start to explain my feelings right now, as I see my return to Old Trafford announced worldwide. It’s like a dream come true, after all the times that I went back to play against Man United, and even as an opponent, to have always felt such love and respect from the supporters in the stands. This is absolutely 100 per cent the stuff that dreams are made of!
“I’m right here! I’m back where I belong! Let’s make it happen once again!
“PS - Sir Alex, this one is for you…”
