The Spain international did not train with Chelsea yesterday but is understood to have told team-mates that his departure from the club was imminent.
A £40m bid for Mata is thought to have been made through a third party on Wednesday although it is understood Chelsea have yet to formally accept a bid from United.
However, Moyes opted not to speak about it following United's painful penalty shoot-out loss at Old Trafford.
Members of the media were informed before the post-match press conference that Moyes would be answering questions on the game only and when asked afterwards about Mata, the Scot said simply: "We are not saying anything."
Nevertheless, it would now be a major surprise if Mata was not part of Moyes' squad for United's next match, against Ole Gunnar Solskjaer's Cardiff at Old Trafford on January 28.
A deal between the two clubs is expected to be agreed later on Thursday with Mata set to become Manchester United's record signing subject to a medical.
Meanwhile Saleh becomes the most recent 'middle of the road' name to turn down Rodgers and Liverpool.- allaboutunited