Chelsea boss Maurizio Sarri has warned his players of an international week hangover.

Ahead of today's clash with Cardiff City, Sarri knows the recent break may affect the Blues' solid form, as he learned during his time at Napoli.

"I remember in my first season in Naples the average points per match during the season was 2.28, but the average after the international break was only 1.31 or 1.32 so I know that the match after the break is very difficult," he told Chelsea's official website.

"Fortunately last season the average was the same, 2.40 during the season and 2.45 after the break, but only because after the first season the players understood the difficulty of the match.

"I am trying to make my players remember this number and telling them about my experience in this situation."