By Karolos Grohmann
BERLIN (Reuters) - Bayern Munich are on a mission with coach Pep Guardiola firing up his injury-hit team as they seek to reverse a 3-1 deficit against Porto in the Champions League quarter-final second leg on Tuesday.
The five-times European champions, who have reached the final three times since 2010, find themselves in the unusual position of having to come from behind.
Guardiola, who has only ever recorded wins as player and coach against Porto, will also be forced to try to turn things around without several of his leading lights.
"People do not know how difficult our situation is," he told reporters after Bayern's 2-0 victory over Hoffenheim on Saturday that kept them on course for the Bundesliga title.
"I will never in my life forget these months and I am proud of the team. Now we have on Tuesday the most important Champions League game. It will of course be difficult but this a is our big goal."
Bayern players need all the pep talk they can get with Arjen Robben, David Alaba, Medhi Benatia and Javi Martinez certain to miss the game at the Allianz (XETRA:ALVG) Arena.
Winger Franck Ribery is also highly unlikely to be fit for the German champions after being sidelined for five weeks with an ankle injury.
Bastian Schweinsteiger, who had been out for two weeks with an ankle knock, did not play on Saturday due to a virus but should be fit along with captain Philipp Lahm.
However, the Bavarians, chasing a treble of titles, have also been rocked by the sudden departure of long-time team doctor Hans-Wilhelm Mueller-Wohlfahrt this week, saying he had been blamed for the defeat in Porto.
"The coach was very emotional (in Hoffenheim)," Bayern midfielder Sebastian Rode said. "He wanted to weld us together. He said we need to remain calm and focussed in this situation and if we believe in ourselves and the team then we can overcome obstacles."
Porto are in fine form, having yet to lose in the Champions League this season and showing superb focus in the first leg to contain Bayern.
The Portuguese edged past Academica Coimbra 1-0 in the league, with coach Julen Lopotegui making nine changes to the squad that beat Bayern.
"We were coming from a tremendously demanding game, both physically and psychologically, and we felt this was our best team at the moment," said the Spaniard of their narrow win. "We had to make some changes, we needed a fresh team to win this match."
With Danilo and Alex Sandro suspended they will need another fresh team if they are to deny Bayern -- who have yet to concede a goal at home in this competition this season -- a fourth straight semi-final spot.
The last time the Porto went through to the last four was when they won the trophy in 2004.