The Englishman faced heavy criticism from sections of the German media following Bayern’s 2-2 draw with Borussia Dortmund in the Bundesliga on Saturday.
He also failed to get on the scoresheet during his side's 2-1 Champions League quarter-final first-leg defeat to the Italians in midweek.
Now, the former Freiburg star has commented that the England captain is "having a bad spell.""Because he hasn't been scoring in the last few weeks, you think about it for a second longer and say, 'Oh, I hope it goes in now.' Just that thought is difficult,” Petersen told Sky Germany.
“Kane is simply having a bad spell at the moment. He had some wonderful finishing moves yesterday (Saturday against Dortmund) and also against Inter.
“A goal with that quality has to come and he just doesn't have it at the moment. He's having a bit of a form crisis."