Barclays Premier League leaders Arsenal take on Marseille in Champions League Group F at the Emirates Stadium on Tuesday.
Here, we take a look at some of the key battles ahead as the Gunners look to close in on the knockout stages.
PER MERTESACKER v ANDRE-PIERRE GIGNAC
The 6ft 6ins German centre-back Mertesacker was again a solid performer as Arsenal moved four points clear at the top of the table with a 2-0 win over Southampton on Saturday. Mertesacker will be out to shackle the goal threat of Gignac, the French forward having scored in both of Marseille's back-to-back Ligue 1 wins.
MESUT OZIL v MATHIEU VALBUENA
Ozil has produced some indifferent displays in recent weeks, but the German playmaker remains the central channel for Arsenal's transition through their midfield. Diminutive Marseille midfielder Valbuena - nicknamed "the small bike" and who scored for France against England at Wembley in November 2010 - will be looking to get the visitors attack going, which stretched Napoli in the 3-2 away defeat on matchday four.
OLIVIER GIROUD v SOULEYMANE DIAWARA
France forward Giroud has earned great praise this season for carrying the Arsenal frontline, grabbing both goals in the win over Southampton - the first with a little help from a blunder by visiting keeper Artur Boruc. Senegal defender Diawara - who had a spell in the English Premier League with Charlton during 2006-2007 - will have his work cut out to keep tabs on Giroud, whose industry has been rewarded with 10 Arsenal goals so far in all competitions.