Jason Naismith was cautioned for a crude lunge on the winger midway through the first half at St Mirren Park.
The challenge came shortly after the home support had been calling for a red card for Thistle right-back Jordan McMillan for a two-footed challenge on Jim Goodwin.
"I think it is six stitches he's got in a knee wound," said Archibald.
"It's just opened right up. I think the boy's blades or studs sliced his knee open.
"I didn't have a chance to speak to him and I never saw it closely. I was just more frustrated because I thought he was causing them problems down that side of the pitch.
"The lad was booked for the challenge and I'm not sure how bad it was, but it's right on the joint of the knee so it's a problem because it's probably going to keep opening up.
"I haven't spoken to the medical team but I think it'll be a couple of weeks anyway."