Pep Guardiola says his injury-hit Bayern Munich must expect surprises at FC Porto in Wednesday's quarter-final, first leg, clash.
Bayern are bidding to reach the semi-finals for the fourth year running, but the 2013 Champions League winners are missing several stars including wingers Arjen Robben, Franck Ribery and Germany captain Bastian Schweinsteiger.
Guardiola is wary of Bundesliga giants Bayern taking Porto lightly, especially as the hosts are missing top-scorer Jackson Martinez, who is out with a groin injury.
"Anyone who reaches the Champions League's semi-final plays at a high level. Porto are a top team and I was completely surprised by their level," said Guardiola in Tuesday's press conference.
"We won't need just one game to get through, we'll need two.
"In 99 percent of our games, the opponent reacts to our pressing game by playing long balls.
"Porto are different, they aren't a side who counter-attacks, they want to play.
"They also have a good pressing game, can switch well, often shift their game and are outstanding in one-on-ones.
"We will need a top performance, both in defence and attack."
Bayern's Germany forward Thomas Mueller and goalkeeper Manuel Neuer are hoping to build on their reputations to help poach an advantage in Porto ahead of next Tuesday's return leg in Munich.
Mueller scored a hat-trick against Portugal in Germany's 4-0 group stage win at last year's World Cup and is hoping to cause more misery for Porto fans.
"It's a reputation that I want to maintain," quipped Mueller.
"We definitely want a good performance for the return leg, but Porto are a very strong team.
"Due to our injuries, the competition for places between us all has become less important.
"It's now crucial to really become a team and we know we won't have many options off the bench."
Neuer in particular has good memories of Porto's Estadio do Dragao stadium having saved two penalties there in 2008 to help his former club Schalke reach the Champions League quarter-finals for the first time.
"I was a very young goalkeeper back then in my first Champions League season," said the 29-year-old.
"Luckily I had a really good day and everything went like clock-work.
"We can expect it to be very loud in the stadium with their emotional fans driving their team on.
"Portuguese players are basically very technical and they are all strong on the ball.
"They have good dead-ball specialists, we will have to be careful and very well prepared."
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