The Chile international was at the club's Carrington training headquarters on Sunday to tie up the final details of his move from Arsenal. He is set to be announced as United's latest signing -- with Henrikh Mkhitaryan heading to the Emirates -- in the next 48 hours.

After flying to Manchester on board a private jet and visiting Carrington, Sanchez was also at Old Trafford on Sunday to film segments for his unveiling while wearing United's No. 7 shirt.

And pictures have leaked on Twitter of the player in his new kit, the images taken by someone watching on from the stands.

He is expected to sign a four-and-a-half-year deal with Man United, while both Mkhitaryan and Sanchez will need new work permits before the deal can be completed.

Sources have told ESPN FC that the agreement between United and Arsenal is a straight swap with no additional fee involved.

According to sources close to the deal, it has been especially complicated because talks with Sanchez and Mkhitaryan have had to run simultaneously.

Jose Mourinho has given his players two days off following their 1-0 win over Burnley at Turf Moor on Saturday. Mourinho said after the game that the move is "so close."

Sanchez is in line to train with his new teammates on Tuesday before a debut against Yeovil in the FA Cup fourth round on Friday night.