Black was substituted out of Sunday's 16-point loss against North Melbourne with a knee injury and will have scans on Monday afternoon to assess the damage.
The 33-year-old initially sustained the problem playing with his eight-month-old son Lachie last week, and aggravated it against the Kangaroos.
Speaking at the Lions' recovery session on Monday morning, Cornelius said he was unsure of the damage.
"I'm not 100 per cent sure if he'll play this weekend or not," Cornelius said.
"If 'Blacky' plays this weekend it'll be fantastic, but if he doesn't I'm sure there'll be plenty of guys ready to take his spot.
"Blacky is a one-in-a-million player, so to have him in the team is always great but those guys (young midfielders) have got to step up.
"The older guys won't be around forever so if we can step up and put in good performances like we did in the third quarter that's very encouraging."
Black remained in Melbourne with a handful of teammates after the Kangaroos' loss and will return to Brisbane later on Monday.
Cornelius was a shining light in the loss, kicking four goals in his return from a two-week absence, and said hosting League leaders West Coast on Sunday presented a huge challenge.
"They've been playing really good footy but stranger things have happened this year, it's pretty hard to pick who's going to win games," he said.
"West Coast have a long flight over and it's always hard to play in the weather and conditions at the Gabba."
Cornelius said he hoped Fremantle had "belted the daylights" out of the Eagles in Sunday's derby, leaving them flat for the trip east.
The Lions have a 3-6 win-loss record but are still searching for credibility after trailing the Kangaroos by a whopping 52 points at half-time on Sunday before a second half rally.
"This week we go into West Coast and we certainly can't give them a head-start, they're a top-four side. I don't think there'll be such a comeback if that happens this weekend," he said.
"It's great to get the wins on the board but if you want to play finals in the future those are the sort of teams you've got to beat. It'd be a great scalp to get."
Michael Whiting covers Brisbane Lions news for AFL.com.au. Follow him on Twitter: @AFL_mikewhiting
