PER MERTESACKER v FERNANDO TORRES
Giant defender Mertesacker has been a consistent performer in the Gunners' rearguard this season, and following injury to Laurent Koscielny will be the man likely charged to keep close tabs on Blues striker Torres, who was back among the goals when scoring in the 2-1 win over Crystal Palace last weekend.
MESUT OZIL v FRANK LAMPARD
Arsenal's club-record signing Ozil has struggled for consistency since his £43million move from Real Madrid, but the German playmaker remains the main conduit through Arsenal's potent midfield. However, up against Lampard, he faces a player immersed in the experience of Premier League big encounters, someone who thrives on them and also with an eye for goal.
OLIVIER GIROUD v JOHN TERRY
Giroud has grown in stature this season, with 10 goals at the spearhead of the Arsenal attack, but despite a high work-rate, the France forward has looked tired in recent weeks. Terry was rested for the midweek Capital One Cup defeat at Sunderland and has been a consistent performer in the Premier League following Jose Mourinho's return to Stamford Bridge, so will relish the chance to shackle Giroud's physical presence in the penalty box.