With Kari Lehtonen likely out, Thomas is expected to become the Stars' top goaltender as they attempt to continue their home surge against the Columbus Blue Jackets on Monday night.
Dallas (31-23-10) acquired Thomas from Florida in exchange for backup goaltender Dan Ellis before Wednesday's trade deadline.
The move could prove vital to the Stars' playoff hopes as they currently own the eighth and final position in the Western Conference with 18 games remaining.
Thomas' first appearance for the Stars came in relief of Lehtonen in Saturday's 4-3 win over Minnesota. He stopped all six shots after Lehtonen left in the third period with a head injury after the Wild's Erik Haula skated into him and knocked his helmet off.
"We know he's not doing that well," coach Lindy Ruff told the team's official website. "It's just a head injury right now. It doesn't look good though."
Ruff is likely to turn to Thomas, a two-time Vezina Trophy winner and the 2011 Conn Smythe recipient while leading Boston to the Stanley Cup.
He went 16-20-3 with a 2.87 goals-against average with the Panthers, losing six of his last eight games with a 3.81 GAA before being dealt to Dallas.
Thomas feels he should be better with the playoffs at stake.
"In Florida, we've been out of the playoffs for a while," Thomas said. "We never really put it together there. For me, (being in a playoff race) makes it easier to play, more fun."
He hasn't had much fun versus Columbus, going 0-2-1 with a 3.51 GAA in four games, and making 26 saves in a 4-1 defeat Feb. 1.
Tyler Seguin, Thomas' teammate on the Bruins, is looking to continue his recent tear. The center has four goals and four assists in two games after failing to get a point in a 4-2 loss at Columbus on Tuesday.
The Stars have dropped four of six meetings with the Blue Jackets, including two at home while giving up seven goals.
Dallas, though, enters this matchup allowing an average of 1.67 goals during an 8-2-1 stretch at home.
Columbus has won four of five, averaging 3.25 goals in those victories.
Artem Anisimov has been an unexpected contributor, totaling six goals and an assist over the past six games. He scored his fourth game-winning goal of that stretch Saturday, while Sergei Bobrovsky had 28 saves in a 1-0 win at Nashville.
"Really since coming back from the Olympic break, his game has been very good," coach Todd Richards said of Anisimov, a Russian Olympian. "He's a trustworthy player, smart player. So, defensive roles, penalty kill, but what we're seeing now is that offensive side of him, and we know he's a talented kid, passer, shooter.
"He's scoring some huge goals for us."
Anisimov has three goals over his last four games against Dallas, with two of them coming Tuesday.
Bobrovsky made 31 saves in that meeting, but he's expected to be rested for journeyman backup Curtis McElhinney, who hasn't started since a 25-save performance in a 3-2 loss to Ottawa on Jan. 28.
He's won his last two meetings with the Stars behind a 1.48 GAA, but hasn't faced them since March 29, 2010, with Anaheim.