Alonso backs Costa to fire at Old Trafford

Football - Sydney FC v Chelsea FC - Friendly Match - ANZ Stadium, Sydney - Australia - 2/6/15 Chelsea's Diego Costa reacts after missing a chance to score Reuters / Steve Christo

(Reuters) - Chelsea striker Diego Costa offers more than just goals and will rise to the occasion in Sunday's trip to face Manchester United despite his recent lean spell in front of goal, wing back Marcos Alonso has said.

Costa's 17 league goals have helped Chelsea build a comfortable seven-point lead at the top of the Premier League table but the 28-year-old Spaniard has failed score in his last five games for the club.