The official Leeds website understands there has been interest from Steve Bruce, but there has been no official approach for the former Norwich and Charlton right-back.
Mills, who signed a new five year deal last season, is included in Sven Goran Eriksson's England squad for tonight's friendly against Croatia at Portman Road, but was left out of Peter Reid's first squad of the season against Newcastle last Sunday.
The right-back responded by questioning his absence from the team on his personal website. Mills' agent Neil Featherby hopes to meet Reid soon to clear up his situation at Elland Road.
Middlesbrough are also understood to have a long standing interest in Mills, but nothing official from the Teessiders has been forthcoming. Arsenal and Chelsea have also been linked with Mills this summer.