SHEFFIELD United have told Nick Montgomery that he can join Millwall for nothing this summer.
Montgomery has a year left to run on his current contract but the League One club will write that off should the Lions want to sign him.
The Leeds-born midfielder moved to The Den on-loan in March but his spell was cut-short by a calf injury after just 20 minutes of match action.
Boss Kenny Jackett has previously admitted he would consider signing Montgomery on a permanent basis, but it is now thought that the 30-year-old is behind at least two players in the club's shortlist of targets.
NewsAtDen understands Montgomery's Blades teammate Kevin McDonald, who is out-of-contract, is another name under Jackett's consideration.
Sources close to McDonald, 23, say he is likely to reject the offer of a new deal at Brammall Lane and move to a Championship club.
The former Scotland U21 international made 31 appearances last season, scoring three goals.