Gianluca Vialli believes a quiet summer of spending is responsible for Chelsea's poor season, and he is backing Leicester to succeed them as Premier League champions.
The 51 year-old Italian, who played at Stamford Bridge from 1996-1999 and was also a manager there, said: "In the summer, the lack of signings at Chelsea was important.
"Normally you create a spark and that did not happen, and I think some of the players were mentally tired."
A summer of change seems likely at Stamford Bridge, and Vialli is disappointed with John Terry's likely exit after he failed to secure a new contract.
"Captain, leader, legend is the banner you see at Stamford Bridge", added Vialli. "I hoped he'd retire at the end of the season so he could stay on in another capacity. It's a pity and as a guy that is still fond of Chelsea I'm hoping that he'll be back in another position."
While Chelsea have struggled, Premier League leaders Leicester have gone from strength to strength, and Vialli thinks Claudio Ranieri deserves a lot of credit.
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"He is the best manager in the world if you give him a club with little expectation and a limited budget. He's good at turning that into something better and achieving great results," Vialli said.
"The key to their success is Leicester defend better than any other team in the Premier League. They are well organised and hungry."
Leicester are five points clear at the top of the table going into this weekend's key clash at Arsenal, but would Vialli like to see them go all the way and win the title?
He stated: "The Premier League has become very democratic, it is not just about the top two or three. Leicester are strong favourites right now, but the other teams are looking at each other and as long as their main rivals don't win it, they don't care.
"But it would be good for football everywhere in the world if Leicester win it."
Vialli was speaking at the launch night for Bradford City's 'Upgrade the Parade', which is a crowd funding project aimed at raising significant funds to redevelop the stadium.