Chelsea manager Jose Mourinho says new signing Kenedy improved the team after he came on in the 68th minute of the game against Crystal Palace.
The youngster was very lively for the Blues but was not enough as they suffered their first home defeat of the season.
The Portuguese was also full of praise for striker Radamel Falcao who scored his first goal for the club.
"Cesar Azpilicueta was fantastic but I took him off because I wanted to give more depth to the side and to play without a left-back and with a kid going forward like Kenedy did," Mourinho said after the game.
"He is a good personality and this is what we needed at the time. Kenedy was responsible for an improvement in the team.
"Falcao's goal means nothing for the team but for his personal confidence it is good and he is fine. From his reaction after the goal you could see his happiness because he has come from a difficult period.
"[New signings] I don't like that [to fix problems with new signings].
"I gave my club the reports of the season and projection on 24 April and don't think now that I am going to say I want this, this and that. We have to do better, me and the players."