Ullmark (lower body) was placed on injured reserve Thursday, Max Miller of NHL.com reports.
Ullmark was injured making a save against the Panthers on Wednesday and was forced to leave the game. With his IR designation, the 33-year-old netminder will be sidelined for at least the next three games, though it could certainly be longer. The Sens brought up Jonas Johansson from the minors and could split the crease between him and Samuel Ersson.