Champions League football is back, and there might be a few surprises.

Bayern Munich manager Thomas Tuchel is cautious about that as they face a Galatasaray team who beat Manchester United in the last round.

Not only that, the Turkish side is also on a 17-game streak.

Galatasaray will be without their top player, Mauro Icardi, but that does not mean they will become weaker, according to Tuchel.

"Galatasaray are more than Icardi," he told reporters.

"The team is very aggressive, very mobile, attacks a lot when in and out of possession. They're a very good and emotive team that's on a long unbeaten run. The results speak for themselves. Winning away at Manchester United is extremely difficult."

Icardi's status for the Bayern game remains to be confirmed, but all signs point to him missing the clash.

The Argentine striker has been on fire for Galatasaray this season, scoring 14 goals in 15 matches. He led his team to a 2-1 victory against rivals Besiktas through a brace but subsequently got injured, putting doubts on his presence for the Champions League return.

Bayern's fractured defense

Aside from the form of their weekday opponents, Tuchel is wary of the state of Bayern's defense, which he previously said lacked depth due to their off-season dealings.

"Now it's about making use of all we have," he said.

"To use all the resources and give the guys confidence," Tuchel said Saturday. "Now we can only recuperate, recuperate, recuperate at the highest level and then we go again in Istanbul."