Chelsea boss Jose Mourinho has conceded that his side's lack of transfer activity over the summer could put their hopes of retaining the Premier League title in jeopardy.

The Blues have added Asmir Begovic and Radamel Falcao to the squad that clinched the top-flight crown in the last campaign, although the club have also had bids rejected for Everton defender John Stones.

Mourinho has admitted that his side's rivals' spending may close the gap to the Blues, but he is confident that his players can step up and improve to fend off the challengers.

He told reporters: "It's dangerous. I think what you are saying, that saying, is right. You say if you stand still you get worse. It's right. But the same people can move forward. You don't need to buy 10 players to be a better team.

"You can be a better team with one or two new players and be a better team, with the same people. The advantage, I hope, the biggest advantage is for them to think together and say together 'my club and my manager they trust me so much.

"They were so loyal to me and they want to show me that they have a good memory. They don't forget easily what I did last year that they didn't spend lots of money. That don't sell me, they don't kick me out. They keep me, they trust me. So now it's my time, now it's our time to give it back and to give my manager, to give my board, my club, a proper answer'."

Chelsea play Swansea City at Stamford Bridge in their Premier League opener later today.