The Toffees are 2/5 (1.40) favourites to sign Mata according to the Paddy Power.
Mata has been linked with a move away from United over recent weeks however, the Daily Mail are reporting that head coach Jose Mourinho may actually decide to give the 28-year-old another chance.
The Daily Record on the other hand report that the Spanish international along with Bastian Schweinsteiger, Marcos Rojo and Daley Blind have all been transfer listed.
The Express report that United would consider offers in the £20 million range for the attacking midfielder.
Everton do however, have competition from across Europe to sign Mata if he does indeed leave – or if he is forced out after the pre-season period.