All the latest ahead of the big game...
Thomas Muller: A goalscoring substitute in the last fixture, Muller missed a fortnight including last week's international with a muscle injury. He returned as a starter against Wolfsburg at the weekend, scoring twice and providing one assist.
Franck Ribery: Ballon d'Or contender Franck Ribery missed the first leg through injury, but is back in action for Bayern. He started at the weekend and like Muller, scored in the 6-1 victory and can be expected to start against Arsenal.
Xherdan Shaqiri: The Swiss midfielder was not even on the bench for Bayern over the weekend and a torn quad which ruled him out of the first leg is expected to do so here.
Arjen Robben: The usually injury-prone Robben has no concerns heading into the return fixture with Arsenal, and can be expected to start at the Allianz Arena, providing two assists at the weekend.
Big decisions: Pep Guardiola has a big choice to make regarding who starts up front, with Thomas Muller impressing as a striker against Wolfsburg in place of Mario Mandzukic. The Croatian will be expected to start but Muller made a strong case for inclusion. Should he play out wide, Franck Ribery, who has just returned from injury too, could be the one to miss out.
Guardiola also has the luxurious option of leaving both Javi Martinez and Bastian Schweinsteiger on the bench, likely to start Thiago Alcantara and Toni Kroos in their place.
Jack Wilshere: England midfielder Jack Wilshere was injured on international duty against Denmark and will be out with a fractured foot for 6-8 weeks.
Kieran Gibbs: Arsene Wenger delivered the bombshell in his press conference that left-back Kieran Gibbs will miss the fixture with an ankle problem. He played in the win at the Allianz Arena last season.
Laurent Koscielny: There was good news regarding Laurent Koscielny who shook off a hamstring injury sustained with France, and featured in training yesterday (above).
Yaya Sanogo: French striker Sanogo has not travelled with the squad due to injury, report The Express. A shock starter in the first leg, it appears Olivier Giroud will get the nod up front.
Kim Kallstrom: Despite reports January signing Kallstrom would soon be back in action, he did not train and is not in contention to feature.
Aaron Ramsey: This is a game too soon for Aaron Ramsey despite his positive progress on his return to fitness. Like Kallstrom he did not feature in training on Monday.
Big decisions: Arsene Wenger admitted there was a possibility Thomas Vermaelen could feature at left-back against Bayern, although Nacho Monreal is the more natural option to replace Kieran Gibbs.
Other key decisions involve selecting a central midfield duo out of Mikel Arteta, Tomas Rosicky, Alex Oxlade-Chamberlain and Mathieu Flamini.
Wenger must also choose who will play out wide. Oxlade-Chamberlain could start on the right as could Serge Gnabry, while on the left Lukas Podolski, Santi Cazorla or Tomas Rosicky could all get the nod.
image: © Jenny Leigh