Chelsea boss Jose Mourinho says new players will join in the summer to add healthy competition to his squad.
The Blues ended their Premier League campaign with a convincing 3-1 win against Sunderland at Stamford Bridge.
And he expects the likes of Arsenal, Manchester City and Manchester United to spend big during the summer transfer window.
"I know that our rivals are not going to accept this title and they are going to fight," Mourinho is quoted as saying by the BBC.
"There are three or four teams that will be aiming for us and we have to be better - me, the players and our squad.
"Maybe they need some fresh blood to keep them under pressure.
"They know me, they know that they are not going to keep their positions on the basis of this year."