The high-profile games are expected to bring even more excitement than Tuesday's fixtures, which featured a thrilling 2-2 draw between Manchester United and Porto.

At Nou Camp, competition favorites Barca face another title contender, who scored 12 goals over two ties in the previous round.

Bayern managed to score in every away game so far in the competition, but this time they are without top scorer Miroslav Klose, who is yet to recover after an ankle surgery.

The Bavarians, who leaked in five goals from Wolfsburg at the weekend, also miss defense duo Lucio and Daniel van Buyten.

However, Luca Toni and Franck Ribery are set to shrug off minor problems and boost Jurgen Klinsmann's side.

Barca almost have an injury-free squad in return, after Yaya Toure and Alexander Hleb were declared fit. Gabriel Milito and Eric Abidal are long-term absentees.

The Catalans are boosted by their 1-0 win at Real Valladolid at the weekend, where the goal-crazy Samuel Eto'o made it 26 goals in 29 games.

Anfield Clash

Liverpool lock horns with Chelsea in a repeat of last season's semi-final, where the latter needed extra-time at Stamford Bridge to reach the final.

The Premiership rivals were paired together several times during the past few seasons in the knockout stage, and Reds boss Rafa Benitez knows all about facing the Blues.

"I am not tired (of playing Chelsea). I am pleased because it means we are playing against a good team at this stage of the competition, which is good for us and them," the Spaniard said.

"My idea is maybe we can do it again for the next five years because it will mean we are playing at this level, which will be positive."

Benitez will miss key midfielder Javier Mascherano through suspension, as Brazilian youngster Lucas is in line to deputize.

Daniel Agger is fit after a back injury, but the Dane is unlikely to take Martin Skrtel's place in defense.

As for Chelsea, Guus Hiddink is sweating over the fitness of Didier Drogba, who is struggling with an ankle injury.

Portuguese full-back Jose Bosingwa is also doubtful after he missed the weekend's 2-0 win at Newcastle with a hamstring problem.