Juan Mata who has not had enough playing time with Chelsea, could be moving to Manchester United but could he bring the Red Devils back up?

It is close for Mata to be joining Manchester United
Chelsea today are in tie with Arsenal and Manchester City to be on top of the Premiership. Juan Mata the Spanish international could be moving to Manchester United, would this be a turn around for Mata?
David Moyes has not started with a bang as expected from fans, could Mata bring around the Red Devils from their defeats they have suffered?