Thomas recently took in a productive loan spell at Elland Road, and Whites boss Neil Warnock was keen to make the arrangement permanent.
He is, however, set to be left disappointed, with there seemingly no deal to be done.
Thomas is looking to see out the season, and his contract, at The Hawthorns, with an unfortunate injury to Zoltan Gera opening the door to possible Premier League football.
"Extending my loan was never really an option," said the 29-year-old winger.
"It was always a case of going out and getting some games.
"I am fully focused on West Brom and until I hear anything different that will stay the case.
"I have still got another six months on my contract, and that is a chance for me to help the club push on.
"I am happy and have been for a few years, so I have no plans to move."