The financial ramifications of failure in England’s Premier League are the most dramatic in sports.

The difference between income inside the league … versus income outside it for the three clubs who will be relegated in May … appears to be something north of 400 million pounds. Maybe around half a billion.

Per club, per season. Mostly driven by a 5.1-billion-pounds TV deal for the world’s most-watched sports league.

Fear of demotion to the second division, and the financial Armageddon attached to it, led to defending champion Leicester City announcing today it had fired coach Claudio Ranieri — who was named Fifa’s club manager of the year only last month for leading City to the 2016 Premier League championship, one of the most astonishing upsets in sports history.

In most sports, in most countries, that sort of triumph would assure a coach of at least one full season of further employment, and probably two.

For Claudio Ranieri, it was good for two-thirds of a season.

And as harsh as that treatment seems, it is difficult to criticize Premier League owners for changing coaches when that half-a-billion threat of relegation becomes palpable.

As it now is, at Leicester.

The champions have not scored a league goal in 2017. They now are only one point clear of the relegation zone.

Leicester could be at the bottom of the table by the time it plays host to Liverpool on Monday night.

I watched Leicester in their Champions League defeat at Seville last night, and they looked limp and undermanned in a 2-1 defeat. It was nearly impossible to see how those guys had won the Premier League.

They lost only one key player from last year’s championship side, N’Golo Kante (now at Chelsea), but he was considered by many to be the most important player at the club, breaking up attacks in his role as defensive midfielder but also launching City’s rapid counter-attacks with excellent passes.

Also, the opposition has adjusted to Leicester’s style. A defense-first approach set up to produce lightning-quick counters has become almost trite in the league, and simply by going forward more carefully the other teams have largely neutralized Leicester — who have averaged less than a goal per match while winning five, drawing six and losing 14.

Ranieri, a 65-year-old Italian, is a fine man and a solid tactician, but the drumbeat of steady defeat, as well as rumors of having lost the respect of some of his players, stampeded the Thai owners of the club to make a change.

The club’s vice-chairman said: “We will forever be grateful to [Ranieri] for what he has helped us to achieve. It was never our expectation that the extraordinary feats of last season should be replicated this season. Indeed, survival in the Premier League was our first and only target. But we are now faced with a fight to reach that objective and feel a change is necessary to maximize the opportunity presented by the final 13 games.”

Thanks for the memories, Claudio, good luck in the future, but too much money is involved for us to allow sentimentality to enter the equation.

And we thought life was tough in American professional sports.