Clarke has caught the eye in Tony Mowbray’s young Black Cats team this season and has played his part in helping give Sunderland a chance of a playoff spot on the final day of the regular Championship campaign.
The former Leeds United starlet is a wanted man, with Brentford and Crystal Palace ready to try to snap him up in the summer.
Sunderland are likely to want to keep hold of Clarke if they win promotion to the Premier League, but if they fail then they have an asking price in mind.
It is claimed that the Black Cats will look for offers over £10m in order to let the winger go.
Clarke, 22, has made 44 appearances for Sunderland in the Championship so far this season, demonstrating his reliability.
The wide-man has chipped in with eight goals and ten assists.
Clarke has had a spell on the books at a Premier League club, having joined Tottenham from Leeds, but failed to break through into the first team in north London.
