Under-fire Stoke City boss Tony Pulis has received the backing of Queens Park Rangers manager Harry Redknapp.
Speculation has been rife the 22-year-old is set to join the west London club in the off-season, with reports in Germany suggesting he had agreed personal terms on a move to Stamford Bridge.
The midfielder is expected to sign a five-year contract with Kevin De Bruyne heading in the opposite direction on loan, but Leverkusen are thought to want the Belgian on a permanent deal.
"Yes, I was in London to negotiate," Bayer Leverkusen sporting director Rudi Voeller told Bild.
"There is nothing more to add. Nothing is decided yet."
According to Kicker, Voeller then travelled to Brussels to meet with representatives of De Bruyne regarding a possible move to BayArena having spent the season on loan at Werder Bremen.