All-action midfielder has been in good form recently, but fears a spell on the sidelines after limping off in defeat at The Hawthorns, ruling him out of international duty
The Austrian international limped out of the match in the second half with apparent ligament damage, with his availability for club and country in question.
"On Saturday it looked terrible, and hurt a lot," said Scharner, speaking to West Brom's official website.
"Hopefully today the results of the scan will not be as bad as I'm thinking at the moment.
"It is not the best and feels, at the moment, serious.
"Austria have a friendly against Ukraine [on 15 November] but at the moment it looks like I'm not going to be available.
"I hope I can use the time to get fit and hopefully it is not a bad injury."