"I just got out of bed and didn't know what was going on," Kovalev said Wednesday after a light skate at the Bell Centre. "I definitely wouldn't wish this on anybody. I heard for some players they were forced to retire. Hopefully it doesn't happen to me."
Kovalev met with doctors Monday and was diagnosed with a form of vertigo that he said arises with sudden movements of the head, and could be gone within two or three days.
"You're afraid to move your head because every time you move it happens to you," Kovalev said. "I spent a day not moving my head, just staring at a point on the wall."
Kovalev skated very slowly for about 10 minutes on his own Wednesday while six of his teammates practised on the other side of the ice. He said he was unsure how he would react to making sudden movements on the ice.
"There's no trust left in my body because every time I turned, my legs felt shaky," he said. "That's why I went on the ice, to get that trust back."
Kovalev hopes to take part in practice with the Canadiens on Thursday, and if he's able to do that he will have a better idea whether he could suit up for Friday's game against the Penguins in Pittsburgh.
"That's what I want to do," he said. "But it's not under my control."
Kovalev's absence in Montreal's big 5-3 home win over the New York Islanders on Tuesday night gave Andrei Kostitsyn an opportunity to get back in the lineup and the rookie from Belarus made the most of it.
Kostitsyn, taken 10th overall by the Canadiens in the 2003 entry draft, played by far the best game of his short NHL career. He got a season-high 16:49 of ice time, assisted on Montreal's last three goals, and finished the night with a plus-3 rating.
His highlight-reel, behind-the-back drop pass to Tomas Plekanec for the insurance marker late in the third period was an indication of the talent he displayed playing with the AHL's Hamilton Bulldogs, where he had 21 goals and 31 assists in 50 games before being called up to the Canadiens on Feb. 22.
Kostitsyn said he had trouble feeling comfortable in previous games because he never knew when his next shift was going to come. But on Tuesday he was able to find a rhythm because he never spent more than two or three minutes on the bench as he played a regular shift with Plekanec and Chris Higgins.
"My first few games with Montreal (this season) I was playing eight minutes a game and I wasn't feeling comfortable," he said. "(Tuesday) night, I felt comfortable."
Back in training camp, Kostitsyn expressed his belief he was ready to make the jump to the NHL and he was very disappointed to be sent down to the minors.
Now that he's back in Montreal, he has no intention of making a return trip to the AHL.
"I don't need to go back to Hamilton, I want to play in Montreal," he said. "It is the best league in the world, the best players play in the NHL. I want to play in the NHL."