The Canadian soccer legend came on as a 76th minute substitute against Hibs at the weekend but six minutes later he was hobbling off the pitch, looking reluctant to put weight on his left knee.
Arfield was a major player in the early months of the season but his form has dipped since celebrating his 32nd birthday on November 1.
Speaking about Arfield’s injury McAllister said:
Scotty’s on route, obviously it’s difficult to find a facility to get a scan for Scotty but he is on route as we speak. Just waiting for the results to come back but it was, it’s quite rare to see Scotty lay down on a pitch and be carried off. He’s generally very robust so it was pretty disappointing to see him come off the pitch the way that he did. We’re hopeful that the scan shows up better than what it looked like (on Saturday).
McAllister seemed very reluctant to discuss the fitness of Ryan Jack who was expected to be back in the squad for the match against Hibs.
Steven Gerrard opted out of today’s media conference.