The German has only played 83 minutes of football since joining Celtic in January.
And isn’t even in the Europa League team to face off against his old team RB Leipzig, he is ‘mystified’ about not getting a chance to play.
Compper said: “I’m fit and I train very well.
“Even my team-mates do not understand why I do not play.
“In the summer I had a calf injury. I got an athletic trainer and a physio at my own expense and made myself fit.
“Now it is up to the coach Brendan Rodgers to finally give me the trust.
“I still have a contract until 2020, but of course I do not want to sit on the bench.
“In August, Celtic suggested to me about a change of club. But I do not want to move on so easily.
“I hope for my chance and want to play.”
Celtic showed a poor defensive display against RB Salzburg as they got beat 3-1.
Compper warned that the Bundesliga outfit will pose an even greater threat and Celtic simply won’t be able to cope.
Speaking to German newspaper Bild-Zeitung, he said: “Some think Salzburg will be stronger than Leipzig, but I do not believe that.
“I hope we take something from the game but it will be very difficult for us.
“We do not defend well, the gaps are not right. If we play against Leipzig like the last time we played in the Europa League, then we’ll lose.
“We won against Hibernian in the last league game. For the league, our individual quality suffices.
“But it will be difficult in Europe. Leigh Griffiths is injured, so we have only one striker in Odsonne Edouard.
“He is a talent but he needs stability.”