Chelsea winger Eden Hazard took a swipe at Werder Bremen after their 3-0 friendly defeat.
Hazard admits Chelsea must improve if they are to be ready for their opening Premier League game against Burnley in a fortnight.
"I don't know what we learned but we try to improve and be ready for the first game," said Hazard. "It was difficult against Bremen, pre-season always is, but we will see after two weeks.
"We played against a small team and they tried to give 100 per cent against Chelsea. For them it is always important.
"I'm happy to be back on the pitch with the team. I tried to give my best but it was my first minutes and it was difficult. I hope the next game will be better. For one month I was on holiday [after the World Cup], I didn't think about football but now I'm back. It's important to win [the remaining friendlies] and do our best to be ready for the first game."
