Jose Mourinho has said that he needed to make four substitutions during Chelsea's defeat to Crystal Palace at Stamford Bridge.
The Premier League champions suffered their second defeat of the season, losing 2-1 to their London rivals following a late winner from Joel Ward.
The manager told reporters at his post-match press conference: "Two or three of them, their individual performance was far from good. I blame myself for not changing one of them because I kept him in the game for 90 minutes.
"When I made the third change I realised that I needed a fourth and I don't have a fourth. [The name of the player] is the last thing I am going to tell you."
Chelsea travel to Everton in their next fixture after the international break.