Last updated on .From the section Celtic

Johnston was forced off in the second half against St Johnstone with a knee injury

Celtic manager Neil Lennon expects Mikey Johnston to be out "long-term" after the Scotland forward suffered suspected knee ligament damage.

The Scottish champions are still assessing the 20-year-old's injury after he went off against St Johnstone on Wednesday night.

"It will be long term," Lennon said. "It was a bad twist.

"It looks like he has twisted the knee and there is a bit of swelling there and ligament damage."

Johnston was injured in a challenge with Saints midfielder David Wotherspoon.

"He says there was contact, but it doesn't look like there was contact," Lennon added.

The Celtic manager said Johnston's decision to stay on the pitch after the injury "might have compounded the problem."

"It was annoying for me because we were making a substitution and he's saying he's ok to carry on but quite clearly after a couple of minutes that wasn't the case.

"We'd already made the substitution, so it's a learning experience if you want to call it that."

Jozo Simunovic looks likely to miss the trip to Hamilton on Sunday after playing four straight matches on his injury return, but winger Mohamed Elyounoussi is to return to training on Saturday having been out since November with a foot injury.

Celtic have rejected an offer from English League One club Gillingham for Karamoko Dembele, with Lennon believing the 16-year-old's development is best served by remaining at Celtic Park for now.

As for the possibility of any incoming transfers before Friday's deadline, Lennon remained coy and reiterated his satisfaction with the current squad.

"We're looking at options but we're not guaranteeing anything," he said. "If we can do some business great, if we can't great because I'm pleased with the squad of players that I've got.

"I might be sitting tomorrow night late on and something might happen, and something might not."