It’s not unusual for what seems an all but confirmed transfer to experience a few hiccups prior to an official announcement.That’s certainly been the case for Nemanja Matic and his imminent switch from Chelsea to Manchester United.The Serbian – who was left in London while the rest of his teammates embarked on a pre-season tour of Asia – has looked destined to leave the Blues since the end of last season.Jose Mourinho has been keen on setting up a reunion with Matic at Old Trafford all summer and is reportedly prepared to offer £50 million for his services.Content with selling the 28-year-old after signing Tiemoue Bakayoko from Monaco, Antonio Conte along with Roman Abramovich are thought to have given the all-clear for him to join the Red Devils.Though the proposed move is not quite wrapped up, it's understood Matic has already undergone his medical at United’s Carrington training complex.The former Benfica midfielder is set to become the third arrival ahead of the 2017-18 season, joining Victor Lindelof and former Chelsea colleague Romelu Lukaku.While it seems very little stands in the way of his formal unveiling as a United player, a rather embarrassing leak may take some of the shine off the occasion.

LEAKED IMAGE

An image of Matic donning the training gear of his soon-to-be new club has emerged on Twitter and potentially revealed his squad number by accident.

After wearing the number 21 for Benfica and Chelsea since 2011, the Serbia international appears set for a change with his favoured option occupied by United vice-captain Ander Herrera.

Based on his clothing in the leaked image, Matic will inherit Bastian Schweinsteiger’s old number 31 shirt after it was vacated when the German left for Chicago Fire in March.

United have not confirmed their official kit numbers for the upcoming season, but it seems they've already decided on several updates.

Lukaku and Lindelof will take two and nine respectively, while Andreas Pereira looks to have been promoted from 44 to 15 if his pre-season shirt is anything to go by.

With Matic poised to become a United player in the coming days, it seems he might not care too much about which number is on his back next season.