#2 Makes sense for United as they are looking to sign a right winger
Last season, Mata made 28 appearances for United in the Premier League, but he's been substituted on five times and substituted off 17 times, making only six 90 minutes appearances for the Red Devils. Jose Mourinho has used him as an inverted winger on the right wing who'll drift inside using his stronger foot which is not a role best suited for him.
Mata played as a no.10 for both Valencia and Chelsea having created and scored more goals in the position behind the striker. United have too many players occupying that role.
Mata, who has a year left to run out of his contract at Old Trafford, having not signed a new one is no longer a part of Mourinho's plan. United could splash the amount received for Mata for a new addition on the right-flank as they've been struggling in that department for a very long time.