Champion Barcelona will be bidding to get its Champions League title defense back on track Wednesday as Arsenal and AC Milan also look to keep the dream alive in the second round of elite European matches. But English giant Chelsea, which has already got its campaign off to a winning start, is set for possibly its toughest group assignment when it meets Spanish side Valencia at the Mestalla. Barcelona was held 2-2 by 2010 champion AC Milan at the Nou Camp in its Group H opener, but despite riding high after a 5-0 hammering of Atletico Madrid in La Liga in which Lionel Messi scored a hat trick, coach Pep Guardiola warned against complacency as the Catalans travel to Minsk to take on Belarus champions FC Bate Borisov. Both sides are level in Group H on one point after Bate drew 1-1 at Czech champion FC Viktoria Plzen. Bate has lost its previous two ties against visiting Spanish sides Villarreal and Real Madrid, but Barcelona's David Villa echoed his coach: “Barca play a very high level of football, but each day is different and no team is unbeatable.” Chelsea boss Andre Villas-Boas' side will be looking to take a big step toward the last-16 when it travels to Spain with striker Juan Mata just one month after he left Valencia for Stamford Bridge. Fellow Londoners Arsenal is second behind French club Marseille in Group F after a late goal gave German champion Borussia Dormund a share of the points. Arsene Wenger is keen his side claim maximum points from the three home fixtures against Olympiakos, Dortmund and Marseille to help it reach the 11-point target he has set to ensure qualification to the knock-out stages. Marseille hosts Borussia Dortmund in the second Group F tie. In Group G, UEFA champion FC Porto travels to Zenit St. Petersburg. Apoel travels to FC Shakhtar Donetsk in the Ukraine. AC Milan hosts FC Viktoria Plzen in the second Group H tie.
