Leicester's decision to sack Claudio Ranieri nine months after winning the Premier League made former Foxes striker Gary Lineker "shed a tear".
Ranieri guided Leicester to the title despite them being rated 5,000-1 shots at the start of the 2015-16 campaign.
The Foxes are 17th this season and lost to League One Millwall in the FA Cup.
"It is very sad," said Match of the Day presenter Lineker. "It is inexplicable to me. It's inexplicable to a lot football fans who love the game."
Speaking to BBC Radio 4, the 56-year-old added: "I suppose you can explain it in terms of a panic decision and for me a wrong decision.
"I shed a tear last night for Claudio, for football and for my club."
In Ranieri's last game in charge, the Foxes lost 2-1 to Sevilla in the first-leg of their Champions League last-16 tie on Wednesday, with the return leg on 14 March.
Speaking to BBC Sport on Friday, Lineker added: "Last season was the inexplicable one, not this season. The fact they are in a reasonable position in the Champions League, they are not in the bottom three and given the magic of last season surely he deserved more time.
"I think that the way everybody got behind Leicester was something I'd never witnessed before. Just to toss that all away over a premature decision and disloyal, lack of gratitude, is quite gobsmacking.
"I think they should be building statues to him, not sacking him."
Ranieri flew back to Rome on Friday, with his former assistant Craig Shakespeare replacing him at the club's scheduled news conference on Friday.
'A sign of modern football'
After news of the 65-year-old Italian's dismissal broke on Thursday, former England captain Lineker, who played for his hometown club for seven seasons, said the "game's gone" in a post on social media.
"It's a sign of modern football, what happened last season was truly extraordinary, " he added on Friday. "The lack of gratitude from the owners of the club and who knows who else involved in such a decision beggars belief.
"That season will remain with us forever, it was truly special and a lot of that was down to the management.
"The same guy cannot be considered incapable of doing the job a few months months later after achieving what, for me, was the biggest miracle in sport."
- Analysis: Were Leicester right to sack Ranieri?
- Reaction to Ranieri's dismissal as Leicester manager
- 'One of the worst things the owners have done'
- 'Craig will step up to the plate'
'Leicester will lose their popularity'
Chelsea dismissed Jose Mourinho as manager the season after their 2015 title and Lineker says while that is "expected at big clubs", the decision to sack Ranieri "takes away from the glory" for the Foxes.
"For a club like Leicester to win the league last season, the magnificence of the story, the likeability of the club under Ranieri - the ultimate gentleman - it kind of demeans the club.
"Leicester were hugely popular right around the world. To do something like this now loses a lot of that popularity."
'A brave decision'
Former Leicester and England goalkeeper Peter Shilton, said the club's struggles this season made Ranieri's sacking understandable.
Speaking to Radio 4, he said: "Going down would be a disaster for Leicester and I suppose the board have made a very brave decision.
"If they stay in the Premier League then they've made the right decision. A lot of people will say there's no sentiment in football, look at what he's done for the club, but he's had a lot of the season to get things going.
"There's obviously some reason why not. We're not privy to that - maybe the board are. Maybe there's unrest in the dressing room, who knows? Maybe the players just aren't performing."
'Please respect my decision'
Leicester owner Vichai Srivaddhanaprabha used social media platform Instagram to explain why he sacked Ranieri.
"We have done our best as management, we do not have only one problem to solve, but there are a million things to do to make our club survive," the billionaire wrote.
"Please respect my decision, I will never let the club down."
The bookies' favourite
Former Leicester player and Manchester City manager Roberto Mancini is the odds-on favourite with the bookmakers to replace his countryman.
The 52-year-old, who won the Premier League title with City in 2012, has current odds of 4-6.
He is followed by former Leicester manager Nigel Pearson, who was sacked in June 2015 (8-1), ex-Crystal Palace boss Alan Pardew (10-1), ex-Chelsea boss Guus Hiddink (10-1) and former Ajax boss Frank de Boer (10-1).
What's the mood in Leicester?
Jason Bourne, BBC Radio Leicester
"There's almost a sense of grief in the city today, with many having lost their 'favourite uncle'.
"Claudio Ranieri was the man that brought the dream to life by winning the Premier League title. It has gone sour this term with players underperforming, new signings not working out and baffling tactics at time from the Tinkerman.
"I thought they would get relegated with Ranieri in charge. I hated to say it. I hoped it wouldn't come true and I'd be proved wrong.
"This gives them a chance. A different kind of chance to stay up."
Phil McNulty, BBC chief football writer:
It is almost the thought that dare not speak its name amid the wave of shock, outrage and disgust at Leicester's decision. But is there actually method in what many see as the madness of the club's Thai owners?
Leicester's fall has been more dramatic than anything they could have foreseen in their worst nightmares. A win for any of Sunderland, Crystal Palace and Hull City this weekend would put the Foxes in the relegation places. Wins for all three and they would be bottom by the time they face Liverpool on what will now be a highly charged occasion at the King Power on Monday.
After 26 games last year they were top on 53 points, two ahead of Spurs. This season they are 17th after 25 games, with only 21 points. Last season they had lost only three games compared with 14 in this campaign, and conceded only 29 goals compared with 43 this term. Indeed, they only conceded 36 in the entire 2015-16 season.
The difference is stark and, very clearly in the opinion of Leicester's owners, dangerous.
Pat Murphy, BBC Radio 5 live
I understand the players were summoned to a meeting by the chairman in Seville after the 2-1 defeat and Claudio Ranieri's fate was sealed by the negative reaction.
The chairman and vice-chairman had become increasingly concerned by the players' alienation from Ranieri this season over a variety of issues, and elimination from the FA Cup at Millwall and the flattering scoreline in Seville hardened the hearts of the influential members of the dressing room.
I understand some influential players, who were part of the Nigel Pearson squad a couple of years ago, were making graphic contrasts with team spirit and the organisational qualities of Pearson compared with Ranieri this season.
The club never really lost faith in Pearson this time two years ago. Despite the fact they were in the parlous position, the general feeling was that he had the dressing room and knew where he was going. He left in the summer of 2015 for different reasons - personal reasons associated with his son, who was on the staff.
The favourite to replace Ranieri is Roberto Mancini, but at the moment it's understood he hasn't been sounded out by Leicester nor is he particularly interested.
|Leicester City: Premier League 2015-16 v 2016-17|
|Pts per game||Shots per game||Clean sheets||Defeats|
|2015-16||2.1 (81 from 38)||13.8 (7th in league)||15||3 (from 38)|
|2016-17||0.8 (21 from 25)||10.8 (14th)||5||14 (from 25)|
What did Leicester say?
On 7 February, Leicester issued a statement saying Ranieri had their "unwavering support". Sixteen days later they sacked the 65-year-old Italian, who had signed a new four-year deal in the summer.
His departure came a day after the Foxes won praise for their performance despite losing 2-1 in their Champions League last-16 first-leg tie at Sevilla.
"Ranieri was told he was sacked on Thursday afternoon in Leicester once the team returned from Spain, but the suggestion is the owners decided before that defeat by Sevilla," said BBC sports editor Dan Roan.
"The decision was taken very reluctantly but the club's owners are desperate to avoid relegation and its consequences."
Foxes vice-chairman Aiyawatt Srivaddhanaprabha said: "This has been the most difficult decision we have had to make in nearly seven years since King Power took ownership of Leicester City.
"But we are duty-bound to put the club's long-term interests above all sense of personal sentiment, no matter how strong that might be.
"Claudio has brought outstanding qualities to his office. His skilful management, powers of motivation and measured approach have been reflective of the rich experience we always knew he would bring to Leicester City."
Srivaddhanaprabha added: "His warmth, charm and charisma have helped transform perceptions of the club and develop its profile on a global scale. We will forever be grateful to him 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 at the start of the campaign.
"But we are now faced with a fight to reach that objective and feel a change is necessary to maximise the opportunity presented by the final 13 games."
'Dilly ding dilly game's gone' - social media reaction
A year (and nine days) in the life of Ranieri
14 February 2016: Leicester lose 2-1 at Arsenal, their final defeat of the 2015-16 season before a 12-game unbeaten run.
2 May 2016: The Foxes are crowned champions of England for the first time in their history as Tottenham draw at Chelsea.
16 July 2016: Midfielder N'Golo Kante leaves to sign a five-year deal with Chelsea.
13 August 2016: Leicester lose their first game of the 2016-17 season - a 2-1 defeat at Hull City.
15 October 2016: The Foxes are hammered 3-0 by table-topping Chelsea at Stamford Bridge.
22 November 2016: Leicester secure top spot in their Champions League group with one game to spare.
18 December 2016: Ranieri is named Coach of the Year at the BBC Sports Personality of the Year awards.
7 February 2017: After a run of two wins in 15 league games, Leicester give Ranieri their "unwavering support".
22 February 2017: The Foxes lose 2-1 to Sevilla in the first leg of their Champions League last-16 tie.
23 February 2017: Ranieri is sacked.