Complex sentence: Liverpool had finished second behind Everton in the 1984--85 Football League, and thus qualified for the UEFA Cup, but victory in the final would enable them to compete in the European Cup the following season.
Split into simpler sentences: Liverpool had finished second behind Everton in the 1984--85 Football League. As a result of finishing second, they had qualified for the UEFA Cup, but victory in the final would enable them to compete in the European Cup the following season.