Cristiano Ronaldo, who is set for a sensational return to Old Trafford after Manchester City pulled out of talks to sign him from Juventus may need to put in a serious fight with Cavani for number 7
The 36-year-old first signed for the Red Devils in 2003 from Sporting Lisbon.
He won three league titles and a Champions League trophy before he departed in a then world-record transfer to Real Madrid in 2009.
During his first spell with United, Ronaldo inherited the number 7 shirt from David Beckham.
He has continued to play with the shirt even at Real Madrid and Juventus.
At Juventus, Juan Cuadrado had to vacate the shirt for the Portugal captain.
However, Edinson Cavani, who joined United last year, has taken the number 7 shirt. Cavani is yet to feature for the club this season, having been given an extended break.
It remains to be seen if the Uruguay striker will also vacate the shirt for Ronaldo, who many years ago registered the CR7 brand for his fashion, menswear and hotel businesses.