Hoops boss Neil Lennon has revealed that the midfielder could need an injection in order to get through Wednesday's meeting with HJK in Helsinki
The 27-year-old missed out due to a hip injury as the Hoops began their Scottish Premier League campaign with a narrow 1-0 win over Aberdeen on Saturday.
But Lennon is now considering taking a short-term approach with the Parkhead outfit holding a slim 2-1 aggregate advantage over their Finnish opponents.
"Scott had a scan on his hip and he has a bit of degeneration in there, on the disc," he told Sky Sports.
"Whether we can get him through Wednesday... we will see how he is on Monday.
"He was very sore yesterday and it's not like Scott. It might mean an injection and hopefully that will calm it down.
"It might need to be seen to down the line but it is not a massive concern for us at the minute.
"It is never a risk when you play Scott but we will work closely with him over the next couple of days and see how he is."
The Northern Irishman has been buoyed however by the return from suspension of Charlie Mulgrew and revealed that he has few other injury worries ahead of the trip.
He added: "Forrest will be fine. Samaras got a kick to the face today and he felt a big groggy. He wanted to give it 10 minutes after the break.
"He is still feeling dizzy so we will have to see how he is, but he should be okay. Charlie Mulgrew was suspended so he will come back into contention."