In-form frontman Quitongo, who has two goals in his last three appearances, was forced off after 62 minutes of the 2-1 loss to Dundee United and the 20-year-old has not trained so far this week.
Giving an update on Jai’s condition, Cappielow gaffer Duffy said: “At this moment in time he hasn’t trained and is still feeling some effects after his hamstring cramped up on Saturday.
“We don’t think it’s too significant, and he’s receiving treatment at the moment, but he’s doubtful for Saturday’s game. It could settle down by the end of the week and he could be fine but as we speak, he is doubtful.”
Celtic loan goalkeeper Ross Doohan was yesterday named in the Scotland Under-21 squad for the UEFA European Championship qualifying double header against England and Latvia.
There was no place for striker Quitongo, who received his first cap in a 4-0 friendly loss against Slovakia in Myjava last November.
When asked if he was surprised at the striker’s omission, Duffy said: “At international level you’re always going to leave out good players because you can only pick so many and you have to get the balance right.
“They obviously got a phenomenal result the last time out, beating Holland 2-0, so I wouldn’t have thought there would be many changes to the group.
“Jai has still got plenty of time ahead of him available for that level and if he keeps performing the way he has been performing then I’m sure he’ll be back in the squad again.
“But he’s not long back from a long-term injury and I’ve got no issues – it’s not for me to tell the international managers who they should pick and who they shouldn’t pick.”
Image: David Bell