Gary Caldwell has questioned James Tavernier's credentials as Rangers captain.

Caldwell was Wigan boss back when Tavernier was allowed to leave and join the Ibrox club in 2015.

The former Celtic defender admits Tavernier, 28, was a talented player whom he admired.

James Tavernier blasts 'irrelevant' jibe from Chris Sutton after Celtic hero brands him 'serial loser'

But his mindset left a little to be desired.

"Is he captain material?", Caldwell was asked on BBC Sportsound.

"I didn't think so, no.

"I let him go along with Rob Kiernan and Martyn Waghorn, for a number of different reasons at the time.

"Financially it made a lot of sense to us, it freed up some wages for me to bring different players in.

"I thought he was an excellent player in terms of his technique, his crossing ability, his free-kicks, his penalties were all plus points.

"He had good energy. But myself and my coaching staff, we all felt that his mentality could have been better."

Chris Sutton says it's last chance for Steven Gerrard and 'serial loser' James Tavernier

By comparison, Caldwell also acknowledged that he could not necessarily see Celtic's Scott Brown blossoming into a skipper when he was raw at 19-years-old.

But the ex-Partick Thistle manager praised his old teammate for becoming a leader on the pitch for Celts and helping them to ten trophies in a row.

He added: "Scott Brown leads that team and in moments of crisis, he’s the one that galvanises the team with a driving run, with a tackle, with his antics in terms of antagonising the opposition.

"It’s all set up to win games of football.

"I wouldn’t have said he was a leader when he was 19 but he’s grown into a fantastic leader that’s won ten trophies in a row for Celtic and he’ll go down as a legend."