Gravesen has failed to make an impact at Celtic Park

The 31-year-old Dane failed to establish himself in Gordon Strachan's first team last season after his �2m move from Real Madrid.

Sunderland and Sheffield United have been linked with a move for the former Everton player.

But John Sivebaek told the Sunday Express: "Thomas wants to prove that he can be a success at Celtic."

Gravesen lost his place to Paul Hartley after the Scotland midfielder signed from Hearts in January and failed to force his way back into Strachan's plans.

Thomas is very happy at the club and very happy with the fans John Sivebaek Thomas Gravesen's agent

Sivebaek said the midfielder had no intention of leaving Celtic Park and was looking forward to next season.

"I think Thomas will still be at Celtic next season. He will fight to get back into the team," Sivebaek said.

"That is the way he wants to act as a professional footballer. I still think he is a really good footballer and I do not know why he has not been playing at Celtic."

Sivebaek added: "Thomas has never expressed a desire to leave Celtic. He is very happy at the club and very happy with the fans."

Strachan said in February he had no problem with Gravesen and that he was part of his first-team plans.