Very different fates, though, await the pair.
While Ranieri will be feted by Leicester City and their fans as a miracle worker, Deila will leave Celtic in the summer as a failure.
For Gianluca Vialli – axed as boss of Chelsea in 2000 four months after winning the FA Cup and less than four weeks after beating Manchester United in the Charity Shield – it just goes to prove that in football anything is possible.
“It is sad, but these departures are part of the game,” said the former Italy and Juventus star, who left Stamford Bridge after falling foul of Ken Bates.
“I was very surprised to learn that Ronny Deila was going to be leaving Celtic.
“He was a winning manager, and it is always strange when things don’t work out for people in that position.
“It does happen in our environment though. I know that for sure because it happened to me.
“I won five trophies in two-and-a-half years with Chelsea, yet was still sent away.
“Of course, we always need to understand what reasons are behind the parting.
“For example, it is clear that even the best managers on the planet will be sacked if the club president decides he wants someone else in charge.”
Ranieri need have no fears on that score with Vichai Srivaddhanaprabha.
Having bought Leicester for £39 million in 2010, the Thai businessman has seen the value of his investment soar, with the Foxes set to bank over £200m from prize money, an improved broadcast deal and Champions League qualification next season.
“I am very happy to see Leicester have this great opportunity to win the Premier League because it is a beautiful fairytale,” said Vialli, who was succeeded as Chelsea manager by Ranieri.
The latter’s 54% winning percentage in his four years in charge was strikingly similar to the 53% they had in the two-and-half years previously under his countryman.
“And I think Claudio really deserves this success. He has done an incredible job, truly exceptional.
“His team has been the most consistent in the Premier League and, though simple, the football they have played has been very effective.
“They work so hard for one another, not just in their starting line-up but everyone in the group. They all contribute and they all fight for one another.
“And, of course, their timing has been perfect because Claudio was absolutely right when he said it was this year or never.
“England’s biggest clubs – the likes of Manchester United, Manchester City, Arsenal, Liverpool and Chelsea – have, for one reason or another, not been able to mount a challenge for the title this season.
“That won’t continue to be the case. They are all looking to the future and will be stronger next season.
“Of that much I am certain.”
None more so, Vialli believes, than the deposed 2015 champions, Chelsea.
“My old club are ready to get back to the top,” said the 51-year-old, who now works as a commentator for SKY Italia.
“They have appointed Antonio Conte as their new manager to take over from Guus Hiddink and, for me, he is the right choice.
“I know from his time in and with Italy that Antonio is a very good, very tactical coach.
“He is someone who is very much in the tradition of the winners he is following – Jose Mourinho, Carlo Ancelotti, Roberto di Matteo and Claudio Ranieri himself.
“I am sure under his charge, Chelsea will get great results because they will get behind him and give him the freedom to recruit the top-quality players he will need.”
Vialli is likewise optimistic Rangers, who only just failed to sign Vialli the player from Juventus in 1996, will be successful on their promotion to the Scottish Premiership.
“Before signing for Chelsea, I really was just one step away from going to Rangers,” he said.
“It was all done, I had reached an agreement on the contract and the Rangers leadership had convinced me to move to Scotland after explaining what their goals and ambitions were.
“But then Chelsea entrusted the team to Ruud Gullit, who called me right away and asked if I would go to Chelsea.
“London was my dream, my first choice.
“For a sports lover like myself, it is one of the best places in the world to live.
“You have some of the most important names in football in the world, also Wimbledon, Silverstone and amazing golf tournaments nearby. It is paradise.
“So when Ruud asked me to join him, I accepted with enthusiasm.
“However, although I wouldn’t call myself a Rangers fan, I’m still very happy they have won promotion to the Scottish Premiership.
“They have history, tradition and incredible fans. They also have a leadership which is handling things better now than in the past, so there is a lot to be excited about.
“To also have the Old Firm derby back is fantastic, great news not just for Scotland but for football fans everywhere.”
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