Lorenz Gunther Kostner has called upon Edin Dzeko to end speculation about a summer move to Chelsea or Manchester City.

Last season the Bosnia striker scored 26 goals in 29 league starts to help fire Wolfsburg to their first Bundesliga title in history.

The 24-year-old pledged his future to the Wolves last summer by signing a new contract and rejecting overtures from Serie A giants AC Milan.

The striker has repaid the faith shown in him by the German side by scoring 18 league goals to help rescue Wolfsburg's faltering league campaign.

Rumours of a summer transfer to the likes of Chelsea and Manchester City have surfaced recently, and Dzeko has said he would be keen to join a Barclays Premier League side at the end of the season.

Kostner admits he is unsure whether Dzeko will stay at the Volkswagen Arena, but he admits he is desperate for the striker to remain at the club.

"Edin Dzeko will finish the season a Wolfsburg player, that's for definite, whatever happens after that is down to rumours," said Kostner.

"Edin Dzeko saying he will stay would be an absolutely huge sign for us. I can't tell you how important that would be for us, but that's neither here nor there. Right now we have to wait to see what happens in May.

"As his manager I can't have much influence on whether he stays or not. All I can say at the moment is that he is on absolute top form. He's really firing on all cylinders. He's doing fantastic."