Chelsea manager Antonio Conte thinks it is difficult for English clubs to succeed in Europe because of the strength of the Premier League.
The Italian is aiming to win the league and FA Cup double in his first season.
Unlike some of their rivals, Chelsea have not been involved in Europe.
Conte said: "This league is very difficult. Every single game you must fight a lot and, I think, also for this reason it's not easy to arrive at the end of a European competition."
In the past six years, five English clubs have reached the quarter-finals of the Champions League, compared to 17 from Spain and 10 in Germany.