Leeds signed the 28-year-old on a permanent deal earlier this summer.
Selling him in the first place rose some eyebrows among Wolves fans, and the reported transfer fee certainly did.
Thelwell is charged with improving Wanderers by making the necessary adjustments in the transfer window, and the man himself has defended the decision to sell Douglas, who is now sitting top of the Championship with Leeds.
"I can see why people would question it on the face of it. Barry is a top professional, a top person and had an exceptional and outstanding season – he should be very proud of what he did for Wolves," he told The Express and Star.
"Things change for a lot of different reasons – that's football. You get to the point where we have to do the best thing for Wolves. Players come in with different characteristics and it should be remembered that Barry had one year left on his contract.
"Hopefully we found a solution where everyone feels they've been able to move forward. Barry is now at the top of the Championship in a very big team and we wish him all the best – him and his family were nothing but a pleasure to deal with."
Douglas is looking like one hell of a signing by the Elland Road club.
They had plenty of instability at left-back last season, but it looks like Victor Orta, Leeds' equivalent of Thelwell, has pulled off an outstanding signing and Douglas might well be joining his old team-mates in the top flight next term.
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