Celtic boss Neil Lennon has revealed Mikey Johnston will be out "long term" after he limped off against St Johnstone on Wednesday night.
The winger came on as a second half substitute in the 3-0 win over the Saints but was forced off after an awkward collision where he hurt his knee.
Celtic are still assessing the full extent of his injury but the Parkhead boss says the youngster suffered suspected knee ligament damage and won't be back any time in the near future.
Lennon said: "It will be long term. It was a bad twist. He says there was contact but it doesn't look like there was contact.
"It looks like he has twisted the knee and there is a bit of swelling there and ligament damage."
The Hoops finished the game with 10 men when Johnston couldn't continue as Lennon had already used all of his three subs.
With Johnston's absence and Scott Sinclair and Lewis Morgan leaving the club this month, Lennon could dip into the transfer market for a wideman before the window shuts.
Speaking after the win in Perth, he said: "Probably. You never say never, but it’s a very difficult time so there’s no guarantees either way. We’ll see."
