He attempted to return for the third period, but after one shift he said he didn't have any strength in the knee and was finished for the night.
That's the same knee that Morrow had problems with in the preseason, when he tweaked it against the Canadiens and missed most of training camp. He has missed six games this season with a variety of injuries, including the tweaked knee.
Morrow's status for Saturday's game against Boston is unclear.
"I know it's a big game, so it's going to take something serious to keep me out of it," Morrow said. "That being said, I don't know how serious this is. It's on my knee, a knee that has given me problems this year and the MCL is a big factor in skating stride, but we'll do our best to try to maintain it and keep the swelling down and hopefully be ready."
Morrow said the training staff wants to look at the knee again on Friday and figure out the next course of action. They did not give him any indication about whether he could or couldn't play Saturday.
Morrow, 32, had two penalties and five hits in the first two periods, playing 12:43 of ice time. The Stars captain has 17 points and 63 penalty minutes on the season.
Richard Durrett is a columnist and reporter for ESPNDallas.com.