The English midfielder scored another stunning goal against Arsenal in the Carabao Cup but had found his playing time limited mainly to cup competitions this season.
Oxlade-Chamberlain was out for over a year with a horrific knee injury and Klopp admits he is yet to find his best form since returning to the team.
Klopp said: “He has scored, nice, both at Genk, a real stunner on Weds, a lot of outstanding moments, but other moments he is not involved.
“We always have to try to reach perfection. He still needs rhythm but that is no problem. He is a long-term project.”
After the game against Arsenal, the England international admitted he has to improve, and Klopp sees that as a positive.
Klopp added: “It is good a player thinks he is not at his best. He could think he is because he scored some goals. Quite some space for improvement. That is good.”