Baba Rahman is set to undergo a medical at Schalke ahead of an expected return to the German club.
The left-back, 23, has been out of action for almost a year, having suffered serious knee injury while on loan at Schalke last season.
He failed to impress after joining Chelsea from Augbsurg in the summer of 2015.
He has made just 15 Premier League appearances, with four of those coming as a substitute.