The Fortuna Dusseldorf board have warned fans not to get too excited about the signing of Christos Tzolis from Norwich City, with the possibility of a resale remaining this summer.

Dusseldorf exercised their option to sign the Greek on a permanent deal after his loan there last season, reported in Germany to cost around £3million.

Speculation had suggested that the quick moving on of Tzolis to turn a profit was on the cards, however, with the likes of Werder Bremen, Borussia Monchengladbach and Union Berlin interested in a move for him.

Now Fortuna board member for sport and communication has added fuel to that fire, saying via the club's official website: "We have exercised the agreed purchase option for Christos Tzolis at Norwich City.

"This is a good moment for Fortuna, but without getting too euphoric. The contract negotiated a year ago could only be concluded with one restriction.

"It contains an exit clause with the possibility for the player to change clubs again during the upcoming transfer period under certain conditions."

Any such move would see City receive a percentage, as they inserted a sell-on fee in the permanent option.

Tzolis will officially return to the Merkur Spiel Arena on July 1, having struggled throughout his three years as a Norwich player.

He joined the club a world-renowned promising talent in 2021, but made just six starts for the club and scored one league goal, with Daniel Farke, Dean Smith and David Wagner all deciding against starting him regularly.

He found form with his loan club last term, however, scoring 24 goals and claiming eight assists in all competitions.