The Armenian playmaker's agreement was seemingly the last piece of the puzzle in the protracted deal, as Sanchez had already agreed terms and had travelled to United's Carrington training ground to complete his medical on Saturday.
Arsene Wenger had previously stated that Sanchez would only join United, if Mkhitaryan moved the other way and it seems that t
The BBC claims that there will be no additional transfer fees involved in the deal, calling it a 'straight swap'.
While many details have been reported regarding the size of Sanchez's new contract at Manchester United, the length and salary in Mkhitaryan's Arsenal deal remains unknown.
Speaking after his side's hard fought 0-1 win over Burnley, Mourinho candidly called the move 'so close', while Wenger admitted it was likely to be wrapped up in the next 48 hours.
Mkhitaryan's agreement is significant in the transfer proceedings because both Wenger and the player's agent, Mino Raiola, stayed bullish that a deal could not be completed without the Armenian coming to the Emirates stadium.
"Sanchez is part of the Mkhi deal, not the other way around," Raiola had said earlier in the week. "Mkhi is going to do what is best for him. He has two-and-a-half years left on his contract, so it's his decision."