Sunderland boss Steve Bruce has revealed that striker Asamoah Gyan was manipulated by "parasites" trying to instigate his move away from the club.

The 25-year-old Ghana international was rumoured to be leaving the Black Cats in the summer, with the likes of Atletico Madrid and Valencia mentioned as possible destinations.

"Since that game at Wembley [against England], all the parasites, as I call them, hover around," said Bruce. "People are in his ear constantly trying to engineer a deal for him.

"Certainly since the England game, when he played at Wembley so well on the night, something has been troubling him.

"It's very difficult, the constant speculation no matter what you try to quash or quell, and the people around him, the people who want to make a fast buck, shall we say, and it affects him in the end."

Despite the speculation, Gyan admitted that he was happy to stay with the Premier League side, and Bruce is confident that he can now resume his focus on the season.

"We have had a discussion with him and he needs now to focus and get himself back on track again and be the Asamoah Gyan we know he is capable of," he added.

"These things affect these players, and it has affected Asa. I had a conversation with him two days ago to say, 'Look, the window as now closed, Asa. Right, we need to see you back playing again and back the way you know you can play'."

The Black Cats face former Premier League champions Chelsea at home on Saturday.