Midfield pressing

Few Champions League matches this season will be so overwhelmingly centred around passing midfielders – Mikel Arteta, Jack Wilshere and Santi Cazorla will face Javi Martínez, Bastian Schweinsteiger and Toni Kroos. The most advanced players like dropping into deep zones to collect possession, while the deepest midfielder on either side are from the Spanish school of reliable distributors, rather than scrappy destroyers.

When astute passing sides face similar opposition, such is their respect for the importance of ball retention that the game usually becomes about pressing, and denying the opponents time on the ball. Bayern can press aggressively and highly effectively, and Arsenal might have to match that over the two legs.

Cazorla v Kroos

Toni Kroos and Santi Cazorla are unlikely to be in direct combat but their movement and positioning will be crucial in the flow and tempo of the game. The two are similar players – they play in an advanced position in a 4-2-3-1 but have experienced playing in a wide midfield role and are comfortable deep in midfield too. Therefore, they can drift around the pitch to collect the ball in a variety of zones, trying to find space where they can.

Kroos is a master of this – his tactical understanding is remarkable and he always seems to be spare, having moved into an unusual position to provide an overload and create a crossing opportunity, or looking to play one-touch passes to bring the wide players inside. Cazorla must not be overshadowed if Arsenal are to progress.

Walcott v Alaba

If Bayern do press, and consequently play with a high defensive line, Theo Walcott will be the most obvious beneficiary. He has become Arsenal's most reliable attacking player this season and has mastered the art of making runs from wide into scoring positions, trying to get on the end of through-balls slid between defenders.

But Walcott will be up against David Alaba, a left-back who possesses similarly devastating pace – and in particular, highly impressive acceleration. Walcott will not be able to rely on his raw speed and make the same run repeatedly – he will have to vary his movement. Alaba can leave too much space in behind, however, and Arsenal must look to exploit this.

Bayern's right versus Arsenal's left

Arsenal have a serious problem at left-back; Kieran Gibbs is injured, Nacho Monreal is cup-tied having played in this competition for Málaga, while André Santos has been loaned to the Brazilian club Gremio. Arsène Wenger has little choice other than to start Thomas Vermaelen at full-back.

Vermaelen could face either Arjen Robben, who loves to cut inside to shoot on his left foot, or Thomas Müller, who drifts inside to become an extra central playmaker and a scoring threat. Fielding a full-back who naturally takes up central positions is not a disaster but in front of him Lukas Podolski's defensive discipline will be tested against his old club by Philipp Lahm.

Wilshere's influence

Jack Wilshere's performance at home against Barcelona two years ago marked him out as a truly exceptional talent. As other Arsenal players struggled to live with Barcelona's high press, Wilshere showcased his ability to receive the ball under pressure on the half-turn, then power on past his opponent to launch a quick attack. Bayern might be a similar test, and Wilshere needs to make himself Arsenal's key player.

Arsenal usually dominate possession at home but Bayern's ball retention might see them playing predominantly on the counter-attack, and Wilshere's ability to lead Arsenal in rapid transitions from defence to attack is crucial. Against the league leaders of a country whose recent footballing identity has been based around smooth transitions, Wilshere has the chance to improve his reputation across Europe.