Odsonne Edouard this summer. The Frenchman was the club's record signing when he joined from Paris Saint-Germain for £9million in 2018 following an initial loan spell.
The striker signed a four-year contract which is up in the summer of 2022 and is yet to sign a renewal. That's put the likes of Milan, Leicester City and Crystal Palace on alert, with Edouard hitting 21 goals in 38 games this season.
And Hartson believes it's certain the France Under-21 international will leave this summer having been denied a move previously.
He said on Go Radio: "We will not be able to keep Edouard, we’ve held on to Edouard with a piece of string really, to be honest with you."He’s been so close to leaving.
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