Forward Patrick Nyarko and outside back Dan Gargan left Wednesday's 0-0 draw with Real Salt Lake at Toyota Park due to injuries.
Gargan left in the 51st minute after spraining his left foot. Nyarko left the game in the 60th minute nursing rib, ankle and groin injuries.
Gargan has had problems with his left foot all season. He sprained his toe which kept him out of the Fire's 2-0 loss in Colorado on April 1.
Nyarko has been nursing a groin injury for some weeks now. He was hit in the ribs and tweaked his ankle Wednesday night.
Both expected to play in Saturday's game against Sporting Kansas City at Toyota Park but want to see how treatment responds over night.