The Bundesliga champions travel to Portugal looking to take another important step in their bid for a domestic and continental treble and are heavily fancied to return home with a healthy advantage.
Bayern are unbeaten on Portuguese soil but, ahead of a re-run of the 1987 European Cup final that Porto won, Pep Guardiola's side have endured something of an injury crisis.
Arjen Robben (stomach), Bastian Schweinsteiger (virus) and Franck Ribery (ankle) will miss out, after Guardiola named just four substitutes in Saturday's league win over Eintracht Frankfurt.
The recent return of captain Lahm has buoyed the runaway Bundesliga leaders, with the German backing his side to progress.
"We are confident enough to say that if we play our game, keep lots of possession and play attacking football, and don't give our opponents many chances, then we will win," Lahm told UEFA.com.
"But they're a dangerous team, with a lot of quality in attack and fast and technically strong players in their squad. We are in the quarter-finals of the Champions League so there aren't any easy teams any more.
"We've just had the international break, so I've had the chance to train for two full weeks and I feel very good. And it's about time to get back into rhythm.
"It's a pity to have missed the round of 16 - that's when [the competition] really starts - but it's nice to be back for the quarter-finals. Being among the best teams in Europe is nice."
Bayern eased into the last eight with a 7-0 aggregate victory over Shakhtar Donetsk, while Porto saw off Swiss side Basel 5-1.
Julen Lopetegui - a former team-mate of Guardiola with Barcelona and Spain - remains in the running to secure both the Champions League and the Primeira Liga during his debut season at the helm.
Porto are without the suspended Ivan Marcano and have doubts over striker Jackson Martinez (groin), but Lopetegui is keen to focus on the task at hand.
"We are prepared for this time of the season," explained the former Spain youth coach.
"Playing the quarter-finals of a competition as big as this one is a reward for everyone and the only thing on our mind is dream and ambition.
"There is nothing else to take into the game."
