Barcelona, AC Milan and Arsenal among the clubs in action
Arsenal's Jack Wilshere, left, challenges Borussia Dortmund's Henrikh Mkhitaryan during their Champions League soccer match at the Emirates stadium in London October 22, 2013.DYLAN MARTINEZ/Reuters
Arsenal's Mikel Arteta (top) is challenged by Borussia Dortmund's Henrikh Mkhitaryan during their Champions League soccer match at the Emirates stadium in London October 22, 2013.EDDIE KEOGH/Reuters
Zenit St Petersburg's Hulk, left, is tackled by Porto's Hector Herrera during their Champions League soccer match at Dragon stadium in Porto October 22, 2013.RAFAEL MARCHANTE/Reuters
Chelsea's Fernando Torres, right, celebrates with his teammate Gary Cahill after scoring a goal against Schalke 04 during their Champions League soccer match in Gelsenkirchen October 22, 2013.WOLFGANG RATTAY/Reuters
Chelsea's Oscar, left, challenges Schalke 04's Max Meyer during their Champions League soccer match in Gelsenkirchen October 22, 2013.INA FASSBENDER/Reuters
Olympique Marseille supporters cheer before their team's Champions League soccer match against Napoli at the Velodrome stadium in Marseille, October 22, 2013.PHILIPPE LAURENSON/Reuters
Arsenal's Olivier Giroud, right, is challenged by Borussia Dortmund's Mats Hummels during their Champions League soccer match at the Emirates stadium in London October 22, 2013.EDDIE KEOGH/Reuters
Atletico Madrid's Diego Costa celebrates after scoring a goal against Austria Vienna, during their Champions League Group G soccer match in Vienna October 22, 2013.HEINZ-PETER BADER/Reuters
Mohamed Salah of Basel tries to score between Mihai Pintilii, left. and Lukasz Szukala, centre, of Steaua Bucharest during their Champions League soccer match at the National Arena in Bucharest October 22, 2013.BOGDAN CRISTEL/Reuters
Arsenal's Mesut Ozil, left, battles for the ball with Dortmund's Neven Subotic during the Champions League Group F soccer match between Arsenal and Borussia Dortmund at the Emirates Stadium in London Tuesday, Oct. 22, 2013.Kirsty Wigglesworth/The Associated Press
Cristian Tanase of Steaua Bucharest, centre, is challenged by Kay Voser of Basel during their Champions League soccer match at the National Arena in Bucharest October 22, 2013.BOGDAN CRISTEL/Reuters
Ajax's goalkeeper Jasper Cillessen grabs the ball as he is challenged by Celtic's Anthony Stokes, right, during their Champions League soccer match at Celtic Park Stadium in Scotland October 22, 2013.RUSSELL CHEYNE/Reuters
Chelsea's Oscar, left, and Schalke's Max Meyer challenge for the ball during the Champions League group E soccer match between FC Schalke 04 and Chelsea FC in Gelsenkirchen, Germany, Tuesday, Oct. 22, 2013.Martin Meissner/The Associated Press
Chelsea's goalkeeper Petr Cech makes a save during their Champions League soccer match against Schalke 04 in Gelsenkirchen October 22, 2013.WOLFGANG RATTAY/Reuters
Austria Vienna's Daniel Royer challenges Atletico Madrid's Miranda (not pictured) during their Champions League Group G soccer match in Vienna October 22, 2013.DOMINIC EBENBICHLER/Reuters
Arsenal's Olivier Giroud (R) challenges Borussia Dortmund's goalkeeper Roman Weidenfeller to score a goal during their Champions League soccer match at the Emirates stadium in London October 22, 2013.DYLAN MARTINEZ/Reuters
Arsenal's Olivier Giroud, right, celebrates with teammate Aaron Ramsey after scoring a goal against Borussia Dortmund during their Champions League soccer match at the Emirates stadium in London October 22, 2013.EDDIE KEOGH/Reuters
Barcelona's Lionel Messi challenges AC Milan's Sulley Muntari during their Champions League soccer match at the San Siro stadium in Milan, October 22, 2013.STEFANO RELLANDINI/Reuters
Marcelo Diaz of Basel celebrates his goal against Steaua Bucharest during their Champions League soccer match at the National Arena in Bucharest October 22, 2013.BOGDAN CRISTEL/Reuters