"They are the wealthiest club and they have a great history in this competition, but in recent years they haven't been as successful as they have been in the past," he said.
"In the last two or three years, they have been a bit disappointing in the Champions League.
"It is becoming harder, even for Bayern. German football is not attracting the foreign players that England attracts, but that is not to say that Bayern will not be a threat.
"They still have some excellent players.
"And one thing's for sure - when you play a German team, you play a team with a very strong mentality."
