An innocuous collision with Gabriel Agbonlahor in the closing stages of the dramatic 1-0 win at Villa Park just after Christmas left the Reds' £18million man writhing in agony.
Initially, there were concerns he had damaged the cruciate ligament in his right knee and his season was over.
To Johnson's relief, a scan the following day revealed only medial ligament damage, although hopes that he would be out for just a month proved overly optimistic.
Nearly seven weeks on from painful night in the Midlands, the 25-year-old defender has just started running again.
By the start of March he should be back in full training and is desperate to play a starring role in the Reds' push for Champions League qualification.
'It's been unbelievably frustrating,' Johnson said.
'The worst thing that can happen to a footballer is being injured, but I'm definitely over the worst of it now and looking forward.
'I'm about two or three weeks away from getting back into full training.
'It was strange when I did it as it wasn't much of a tackle. The lad fell on me and then I heard something in my knee snap so I knew it wasn't good.
'The following morning they thought it might have been my cruciate. It was a relief when I found out it wasn't. That was some good news from the bad news of getting injured.
'For the first four weeks I was on crutches and locked in a knee brace so I could barely move.
'But since then I've been doing lots of stability and strengthening work to try to get the muscle back and recently I've started jogging again.'