The 25-year-old has not been as effective for the Scottish Premiership leaders this season.
Celtic midfielder Stefan Johansen has made an admission that his form was not good enough earlier in the season, but has insisted that he is starting to get back to his best, The Scottish Sun reports.
The Norwegian has started 17 games for the Hoops in the Scottish Premiership this season, but has been unable to really stamp his authority on games in the way he has done previously. But he claimed that after a poor spell, he is gradually getting stronger.
"As I have said before, I am dissatisfied with the way I was playing in the autumn," he told The Scottish Sun.
"But in recent months I have felt my rhythm is better and that the body is good. I'm not worried about form."
The one area that he has been severely weaker in this term is his goalscoring. Last season, he scored 13 goals in all competitions including nine in the top flight to help Ronny Deila's men win the title by 17 points. That total meant that only Leigh Griffiths and Kris Commons scored more times in the league than the 25-year-old.
However, this term he has scored just four times in all competitions with just one strike coming in the league. His failure to rediscover his form from last term has arguably been one of the reasons that the title race has been as close as it has been this year.
But with Johansen now confident that he is finding his best form once again, Deila will be hoping that he can help the side take advantage of Aberdeen slipping up in the league and help them to glory in the Scottish Cup.