Johansen has struggled since the start of the season and Ronny Deila has left him out of his starting line-up on a few occasion.
“It has also affected my hamstring and the front of my thigh.
“We thought we had got to the root of what was causing the injuries, but then I got another knock against Fenerbahce and that set me back again.
“After the games, I was in a lot of pain. It is very frustrating because I have never suffered from any real injuries before.
“It’s been better in the last few days. When I get rid of the back pain, then I think all the other problems should stop, too.
“I have had a good chat with Ronny Deila about my problems.
“Sometimes my thigh hasn’t felt right and I have to take time to recover, which means I am not right for the next game.
“It’s been tedious because I can never get into a rhythm when you play every week.”