The former Aston Villa man, who can play anywhere across the back four but has spent much of this season at full-back, has little more than a year left on his Doncaster contract.
And the Sun reports that has attracted interest from 'a host' of other clubs, including Sunderland, Birmingham and Hull - while Leeds United are also namechecked.
Is survival key to Mason signing?
Sunderland, though, are the worst-placed of all the allegedly interested parties, the rest of whom are at least five points clear of the bottom three.
The second-from-bottom Mackems are eight points adrift with only six games remaining, which could leave Birmingham and Hull in a straight fight for the former Real Madrid youngster's signature.
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