Complex sentence: UEFA.com, 22 July 2006 and a mere month into the league season, he suffered a serious injury, tearing the cruciate ligament in his right knee; after returning to activity in April 2007, he suffered the same injury two months later.
Split into simpler sentences: UEFA.com, 22 July 2006 and a mere month into the league season, he suffered a serious injury, tearing the cruciate ligament in his right knee. After returning to activity in April 2007, he suffered the same injury two months later.