Chelsea midfielder Frank Lampard has blamed 'certain people' for undermining the club's title challenge.
Jose Mourinho's side had been chasing a third successive Premiership crown, but will have to settle for second spot this term after Sunday's draw at Arsenal ensured Manchester United would clinch the 2006-07 title.
"There have been problems at the club and they have to be addressed, simple as that," Lampard told The Sun.
"There are things we have been battling against and we have to put them right. We cannot allow certain people to lose us the spirit that has got us to where we are.
"You will understand what I mean when you look at how we played at Arsenal, with 11 players all fighting to win the game.
"All our players involved in that performance can take pride from their efforts and look forward to better things.
"That's who we are and what we are about as a club, and next year we have to make sure we are focused on being champions again."