Complex sentence: After impressive showings in Benfica's 2005-06 Champions League campaign, which ended after they were knocked out in the quarter-finals by Barcelona, Manchester United and Lyon were linked with Petit; however, he was reluctant to leave one of his favourite clubs.
Split into simpler sentences: After impressive showings in Benfica's 2005-06 Champions League campaign, which ended after they were knocked out in the quarter-finals by FC Barcelona, Manchester United and Olympique Lyonnais were linked with Petit. However, he was reluctant to leave one of his favourite clubs.