Thomas is fresh back from a loan at Leeds United.
Keen told the WBA website: "Has he got a future at the club? That's something you'd need to speak to him and Steve (Clarke) about.
"He's a massive part of the squad between now and the end of the season and because of the injury situation he could have a really big part to play.
"He could become a mainstay in the team.
"We'll have to wait and see."