Bristol City manager Lee Johnson has confessed that he could face a battle keeping Aden Flint at the club, as the defender has "had his head turned" by Birmingham City.

The 28-year-old is reportedly wanted by a number of second-tier clubs, including promotion-chasing trio Aston Villa, Fulham and Middlesbrough.

Birmingham have also joined the race for Flint's signature, meanwhile, seeing their initial approach knocked back for both the 28-year-old and teammate Joe Bryan earlier this week.

Commenting on the ongoing speculation surrounding Flint's future, Johnson admitted that the centre-back may already have made up his mind.

"He's a good lad, Aden - he's definitely had his head turned, there's no question of a doubt about that," he told reporters. "In the summer we had a conversation with the agent. The agent made it clear that there is interest. And if there is interest where Aden can maximise his earnings and his potential moving forward then they would be interested in exploring it.

"Obviously Aden was really happy to sign his new deal where he was handsomely paid due to the quality of the performances he put in through the years. And this is the catch 22: every player wants to play as high as they can and for as long as they can and we hope that's for Bristol City."

Flint featured in each of City's 46 Championship outings last season, scoring five times from the back.