Clubs are on alert after former England midfielder Stewart Downing was told he can leave Middlesbrough on a free transfer this summer.
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Garry Monk has wasted no time assessing his squad and has told Downing - a former Sunderland target - that he can leave on a free, although it is understood to have been an amicable decision.
The 32-year-old midfielder still has two years left but has been informed he is free to leave.
Downing, who returned to his home-town club in a £5.5million move from West Ham in July 2015, won't be shy of admirers with Crystal Palace among the clubs to have shown a serious interest in him back in January.
Then he was linked with a loan move but will be available on a permanent deal for nothing this summer.
Downing enjoyed a short loan spell at the Stadium of Light earlier in his career, scoring three goals in seven appearances for the Black Cats between October and December in 2003.
Sunderland battled Boro for his signature two years ago but he decided to head back to the Riverside.
Speaking at the time, Downing said: "The clubs in the Premier League (who showed interest) were no better than West Ham.
"It might be mid table football with nothing to play for.
"Sunderland were the first to make an offer to West Ham, but as soon as I spoke to Middlesbrough that faded away.
"No disrespect to Sunderland, I’ve been there on loan and had a good time there.
"But when I knew Boro wanted me there was only one place I wanted to come and (chairman) Steve Gibson is a very persuasive man."