Borussia Dortmund chief Michael Zorc says they'll fight to keep hold of midfielder Ilkay Gundogan.

The defensive midfield schemer has been linked with Manchester United and Arsenal in recent weeks, with German sources claiming United have made a firm approach this month.

Gundogan's deal runs to 2016 and Zorc is upbeat over their chances of tying him to a new agreement.

"We are in good conversation with him. From my vantage point a contract extension makes sense for both sides," said Zorc.

"Illy was very young, before his injury. He was the best footballer for his age and now has not yet reached his zenith."