Chelsea manager Jose Mourinho says "without him", captain John Terry would not still be at the club.
Terry, 34, has played every minute of every league match this season, skippering the Blues to their fourth Premier League title triumph.
"I think he knows that, without me, he probably wouldn't be at Chelsea in this moment," said Mourinho.
"But I also know that, probably without him, I would not be again Premier League champion."
Former England captain Terry fell out of favour somewhat under previous managers Roberto Di Matteo and Rafael Benitez and despite winning the Champions League in 2012 and Europa League in 2013, Chelsea had not won the league since 2010 before reclaiming the title this season.
Having been a mainstay in the Chelsea defence this season, Terry was rewarded with a new contract in March, extending his stay at Stamford Bridge until the end of the 2015-16 season.
Mourinho, who returned to manage the London side for a second spell in 2013, paid tribute to the centre-back.
"I thought he was in trouble. I thought he was over," said the Portuguese, whose side also won the League Cup this season.
"He hadn't played for the previous two years, two or three consecutive matches. I thought there was something wrong and that he couldn't get back to his normal level.
"Probably, with another manager he wouldn't play. And without playing he wouldn't have another contract.
"I always thought he was going to improve and I'd have a good player. But, in the end, he came to a fantastic level. He's had a magnificent season."
Chelsea visit West Brom on Monday, before finishing their season at home to Sunderland on 24 May.