Bayern Munich's preparations for a must-win Champions League second leg against FC Porto was not helped by the decision of the club's doctor to down tools last week.

Hans-Wilhelm Muller-Wohlfahrt felt as if manager Pep Guardiola was pointing the finger at him and tonight on Off The Ball, European football correspondent Graham Hunter gave us the background to the conflict between doctor and the leader of the patients.

"Very nearly since day one, Guardiola has been dissatisfied with almost everything about the existing arrangements with the medical department at Bayern Munich. Muller-Wolhfahrt would be the principal reason with his autocratic way and the impression he's given to Pep Guardiola about 'I've been here forever, you're just passing through. We're not doing it your way, we're doing it my way,'" he explained.

"That it was Muller-Wohlfahrt who quit rather than Pep getting his way means it's a very pyrrhic victory and a very clever thing for the doctor to do. It's my impression that the doctor believes that this will polarise opinion against Pep Guardiola, will increasingly see Guardiola under pressure and will probably then, in Muller-Wohlfahrt's mind, see him back at the club once Pep Guardiola is gone. It's a medical battle that Pep wanted to win - but not in this way."

German football writer Rafa Honigstein also joined us ahead of the Porto match to give us an insight into the political situation at Bayern.

"Internally he's safer and more secure than he's ever been. Bayern would bend over backwards to extend the contract with him and they're absolutely happy with what he's doing. The players like what he's doing and the board like what's he's doing. They won't like getting knocked out tonight, but they are very much realistic and there's no one they can think of who they'd rather have coaching them next season," said Honigstein.