The midfielder’s contract is due to expire at the end of the season, with negotiations over an extension yet to be agreed.
Mata has been at Old Trafford since signing from Chelsea for £50, in January 2014, but reports in his home country say he could be heading back to La Liga.
Sport reports that the playmaker is on the radar of Atleti, who could bring him in on a free transfer if the 30-year-old fails to agree a new contract with the Red Devils.
Mata has been in England since arriving at Stamford Bridge from Valencia the summer of 2011 but has struggled for regular game time this season, scoring two goals in 20 Premier League appearances.
Get the best features, fun and footballing frolics straight to your inbox every week.
Thank you for signing up to Four Four Two. You will receive a verification email shortly.
There was a problem. Please refresh the page and try again.