Ericsson has missed the last four games with a lower-body injury that he suffered March 12 at Montreal.
"I'm not exactly sure but I think I was trying to kind of protect, going for the puck and it was (Brendan) Gallagher kind of falling on my leg," Ericsson said. "My skate kind of got stuck and he kind of fell over it and I fell over myself, too."
Things appear to be moving in the right direction for Ericsson after the optional practice.
"It was my best day today by far," Ericsson said. "It felt better. I tried to test it a little more today and it was pretty good."
Wings coach Jeff Blashill said they would wait until tomorrow to see how Ericsson responds but said he will not play against the Golden Knights.
Trevor Daley has essentially been ruled out for the rest of the season due to a lingering back issue so the Wings had recalled Libor Sulak under emergency conditions Wednesday.
Sulak practiced with the team in St. Louis but he ended up being too ill to play.
"I don't know what the odds are of that, but that's a little unlucky," Ericsson said, shaking his head.
Sulak was not among those skating Friday.
"He's still not here (practicing), so I'd rule Sulak out for tomorrow as well, just based on the fact that he hasn't been able to skate the last few days," Blashill said. "If he's that sick to where he can't get here, then obviously, he's not ready to play."
Mike Green is out for the rest of the season because the virus that kept him out the first nine games of the season resurfaced. He has missed 31 games so far this season.
Daley has missed 30, which includes the time out recovering from the broken foot he suffered blocking a shot in the morning skate on Dec. 31.
Ericsson has missed a total of 20 games this season.
Danny DeKeyser missed 27 games earlier in the season.
Niklas Kronwall missed the first three games of the season but has played in every game since then.
Even rookie Dennis Cholowski, when he was with the Wings earlier, missed two games with a minor injury.
"It's been a little different for sure," Ericsson said. "There's been a lot of injuries. Too many. Myself a few times this year and some of the other guys a few times, so it's frustrating, especially because you never get any good rhythm. You come back and maybe you're not feeling the best when you come back and you're basically playing a little banged up. It is what it is."