Former Chelsea chief Peter Kenyon admits much of the management structure still at the club was built for Jose Mourinho.
The Real Madrid coach is tipped to return to Chelsea next season.
Kenyon told BBC Sport: "We brought Jose in because we had John Terry, Petr Cech, Joe Cole and Frank Lampard but we had no experience of winning anything.
"We were looking for a coach who could reignite and get the best out of a very good bunch of players and start implementing structures that would set Chelsea on a course to being a very key European club.
"He was integral to the ongoing success after he left because of some of the structures were put in with him being very much at the forefront. He has continued to be part of Chelsea and he has a remarkable rapport with the fans.
"We went from not winning the league for 50 years to winning two on the bounce, we broke up Manchester United and Arsenal's dominance. There was a key component of starting to establish Chelsea as a major European force."