Morrison sustained a groin injury during West Brom's Premier League defeat by Swansea at The Hawthorns.
The Albion ace was substituted at half-time and faces a race to be fit for Friday's game with Belgium at Hampden Park.
West Brom boss Steve Clarke stopped short of ruling Morrison out of that match and the trip to Skopje four days later, but admits the player may struggle to recover.
"He felt a pain in his groin just before half-time, the last couple of minutes in the first half," Clarke said.
"The medical people will assess it but I would imagine he is doubtful for the Scotland trip."