Celtic manager Martin O’Neill explained Alistair Johnston “felt something again” after his substitute appearance in the win over Hibernian was cut short.
The Canada right-back, 28, missed most of last season with hamstring issues and had been absent since early August with a recurrence of the injury.
His appearance off the bench at Easter Road in Celtic’s 2-1 victory lasted 21 minutes.
“We’re not sure just at this moment,” O’Neill told BBC Scotland.
“When you’ve had a couple of hamstring problems, I think that your concern is anything you might feel is a bit of a niggle.
“I don’t know. He’s not sure, neither is the doctor at this minute. He’ll obviously need a scan and we’ll see how he is.”
More positively for O’Neill, central defender Cameron Carter-Vickers came through the final 17 minutes after taking over from Johnston. The United States defender had been missing since mid-September.
“Of course, we need every single body back,” O’Neill said.
“He seems to have come through the game OK. Delighted that the big players are back.”