The Mirror reports that Sunderland are keen to sign Fletcher, should Wolves get relegated to the Championship.
Fletcher has scored 10 goals for Wolves this season.
O’Neill confirmed: “I’m going to have to look at strengthening the squad.
“In the last couple of games we might be able to look at some of the younger players and see how that works out, so we have a viewpoint on them for the summertime.
“But I still feel we need to strengthen.”
