Slovakian international Karhan infuriated Wolf following a string of lacklustre performances, and the last straw appears to be an interview in which he stressed that he is not enjoying football these days.
Wolfsburg have disappointed this season, after starting the campaign with high expectations, as they are far away from a top-five finish and face a must-win game at Gladbach in order to stand any chance of qualifying for Europe.
"Miroslav has failed to act like a proper skipper. He should have let by example, but that's not what he did," fumed Wolf, who will leave the club this summer.
Effenberg had turned down a move to Hamburg this week and Wolf's vote of confidence makes it even more likely that he will extend his spell at Wolfsburg this summer.
