It was the first time Lehtonen faced shots since sustaining a concussion in the third period of a 4-3 win against the Minnesota Wild on Saturday.
Lehtonen left the ice 6:37 into the third period Saturday after a collision with Wild center Erik Haula. Lehtonen's head hit the crossbar after Haula knocked off Lehtonen's mask.
Tim Thomas, acquired from the Florida Panthers prior to the NHL Trade Deadline, came on in relief of Lehtonen on Saturday and picked up his first win with the Stars. Thomas has started the two games since, including the game postponed on Monday with the Columbus Blue Jackets after Dallas center Rich Peverley collapsed on the bench early in the first period.
Thomas will start Friday against Calgary, with Cristopher Nilstorp, recalled from Texas of the American Hockey League on Sunday, serving as his backup.
Lehtonen, who is 25-16-10 with a 2.47 goals-against average and .917 save percentage, could return Sunday when Dallas plays at the Winnipeg Jets.
"Kari will get tested," Stars coach Lindy Ruff said. "Obviously he's looked good the last couple days. He'll go through his protocol. We'll get an update later [Friday] and if that update is good he'll be available in all likelihood to play our next game."
Dallas has 17 games remaining in the regular season, so Ruff is happy about having veterans Lehtonen and Thomas possibly healthy and available for the Stars' stretch run.
"I look at that as a great option," Ruff said. "We're in some really tight parts of the schedule and we need both guys, and to get Tim some valuable playing time and to have Kari back that there's times that we don't have to go four or five games [with the same goalie]. We can go a couple games and get either guy to play. I think with the amount of games, and it's such a short schedule, that to get him [Lehtonen] back by Sunday is a great option for us."