Celtic could've had the now-Wolverhampton Wanderers star in 2015.
If Southampton are relegated from the Premier League, Wolverhampton Wanderers will reportedly try to sign left-back Ryan Bertrand.
Sunderland play host to Wolverhampton Wanderers in the Championship on Sunday.
Wolves star Barry Douglas has been one of the club's biggest commodities this season.
The Wolverhampton Wanderers defender chalked up his first goal of the season at the weekend.
Barry Douglas has been one of the highlights of the season for Wolverhampton Wanderers.
Wolverhampton Wanderers won against Middlesbrough at the Riverside Stadium in the Championship on Friday.
Scottish Premiership giants Celtic lost out to Championship title favourites Wolverhampton Wanderers this summer for the signature of Barry Douglas.
Wolves left-back Barry Douglas had to wait 10 years before earning his debut for Scotland, which he finally achieved last night.
Celtic left-back Kieran Tierney has been forced to withdraw from the Scotland squad following an injury.