Coutinho joined Barcelona from Liverpool in a £142m switch in January 2018 but failed to make his mark at the Camp Nou and was loaned to Munich in the summer, registering two goals and three assists in his first ten games.
“For me, he is a stranger in the team,” Hamann told Sport Bild. “I cannot remember a good situation [he made] in attack.
“If you have such a player in the team and he does not show any special moments, then, of course, you get problems because in the defence he only counts as half a player.
“He has 30 or 35 games left so he has to start sometime. He is still on loan from Barca until the end of the season.”
Coutinho played all of Bayern’s 3-2 Champions League win at Olympiacos on Tuesday and head coach Niko Kovac defended the Brazilian’s performance.
“At the moment he lacks a little bit of luck,” he said. “He always has good actions. I am very satisfied with his performance as well as with the performance of the others.”
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