(1:38)Chelsea defender Levi Colwill faces a long spell out of action after undergoing surgery on an anterior cruciate ligament injury. The club said Thursday that England international Colwill had "successful surgery" after "medical assessments confirmed surgery would be the required course of action." Levi Colwill had surgery on an ACL injury. Image Photo Agency/Getty Images"It was in the first session on Monday, just in the last minutes of the session," Maresca said in a news conference. Chelsea kick off their Premier League campaign at home to Crystal Palace on Aug. 17.