Wenger left Sanchez out of his squad because the player has travelled to Manchester ahead of his move.
"Since I was a young lad I've always said that my dream was to play for Manchester United, and I'm not just saying that because I'm here now and today it's come true", he told MUTV.
Sanchez will earn £350,000 a week plus an extra £100,000 a week for image rights over the course of a four-and-a-half-year contract.
Sanchez's arrival also comes with a £10m sign-on fee, a £15m fee for his agent, Fernando Felicevich, and a £35m transfer fee.
"I expect soon or never", Mourinho said after his side's 1-0 win against Burnley. "So close, so close, so close, if it doesn't happen it is not going to happen", Mourinho said, according to the Mirror.
However, Spanish football expert Balague has claimed that Sanchez will not be officially presented to the media as a Manchester United player until Tuesday.
"I think that also gets through to the player".
"We're replacing a very good player with a very good player, a world-class player with a world-class player".
Mkhitaryan spoke to Arsenal's website after signing his contract; "I'm very happy that we could finish this deal and I'm very happy to be here".
"I can not understand anybody wanting to leave Arsenal", Wenger said.
Sporting director Txiki Begiristain outlined the January plan for the Premier League leaders, following rumours the deal for Evans has already been agreed - which both clubs have subsequently denied.
Given Sanchez's contract expires in the summer, and the Gunners seemed willing, if necessary, to lose him for nothing, acquiring Mkhitaryan could represent something of a coup if Arsene Wenger can integrate him quickly into the starting XI.
"As long as it is not over the line you can not say it will happen".