Can Sarri recover authority at Chelsea after Kepa incident?

The Spaniard twice required treatment late in extra-time against Manchester City at Wembley, with the match heading for penalties, so the Italian boss planned for his substitution.

Willy Caballero, who saved three penalties for City in their 2016 League Cup final win, was readied to go on, but Kepa declined to leave the pitch - sparking confusion and angering Sarri.

Even after the bizarre incident, the world's most expensive goalkeeper had the chance to be a hero.

WATCH: Bizarre!... Sarri goes mental as Chelsea goalkeeper refuses to be subbed

He saved Leroy Sane's penalty in the shootout, but could have done better with Sergio Aguero's effort that slipped under his body as Pep Guardiola's side retained the trophy with a 4-3 shootout win after a goalless draw.

Victory at Wembley might have bought Sarri time, particularly coming so soon after a 6-0 humbling by the same opponents in the Premier League.

But instead the 60-year-old Italian, who is yet to win a trophy in his managerial career, must prepare his players to host high-flying Tottenham in the Premier League on Wednesday, knowing he cannot afford to slip further behind the top four.

Sarri, Kepa and David Luiz, the closest player to Kepa throughout the incident, were "on message" after the match at Wembley, all insisting it was a misunderstanding, not insubordination.

"The coach has the power over the group. He has our respect," Luiz said. "For me, there is not a problem here for that. We all believe in his philosophy, we all believe in the way he wants us to play."

But former Chelsea skipper John Terry said the former Napoli coach was in a difficult situation, with the incident coming after weeks of speculation over his future and concerns over his style of play, dubbed "Sarri-ball".

"It leaves Sarri in a tough place," he told Sky Sports. "I'm surprised he didn't force him to come off."

Ex-Chelsea striker Chris Sutton described the scenes as "mutiny at Chelsea".

"Kepa should be sacked, not Sarri," he told BBC radio. "He's been undermined - it's the worst thing that can happen to a manager."

REACTION: Fans edit Kepa's Wiki page to 'Manager of Chelsea' after Sarri row

Under International Football Association Board rules "if a player who is to be replaced refuses to leave, play continues" and it is not the first time it has happened.

In the Premier League in April 2017, while at Swansea, Lukasz Fabianski was injured in the 81st minute, declined a change in the 86th minute and conceded three goals afterwards as a 1-0 lead turned into a 3-1 loss to Tottenham.

Chelsea's history suggests players hold significant influence at Stamford Bridge. The hire-and-fire policy of owner Roman Abramovich means managers have a limited shelf life and players have previously exploited the policy.

This is not the same group as the one that defied Andre Villas-Boas or masterminded a Champions League win under Roberto Di Matteo, when the senior players were said to be more influential than the interim manager.

But the incident suggested there could be a leadership vacuum at Stamford Bridge.

Sarri replaced Antonio Conte in July and got off to a flying start, with Chelsea unbeaten for the first 18 competitive games.

But recent results have included the 6-0 mauling at City, a 4-0 loss at Bournemouth and a 2-0 defeat by Manchester United in the FA Cup at Stamford Bridge.

After the Spurs game, Chelsea have a run of what appear to be winnable fixtures before away matches against Liverpool and Manchester United in April.

But the question is whether Sarri still has authority in the dressing room and whether he will be given the time to turn things around.