Kepa was furious. Wildly gesticulating with his arms, the world's most expensive goalkeeper forcefully indicated to Sarri he would be ready to face penalties against Manchester City with the Wembley showpiece locked at 0-0 and extra time about to end.
But Sarri was determined to bring on Willy Caballero, who saved three spot kicks in the 2016 League Cup final while in City's winning side. So Kepa, who joined Chelsea in August for 80 million euros (then $93 million), simply would not leave the field.
"It wasn't that I was refusing to be substituted," Kepa said later, after being beaten by four penalties in City's 4-3 victory in the shootout. "It was a way of trying to tell the bench that I was fine."
But Kepa's behavior wasn't fine at all, according to former Chelsea captain John Terry. "Once your number goes up you have to come off and show a bit of respect," Terry said in the Sky Sports television studio at Wembley. "Deal with that after."
Publicly humiliated with his authority undermined, Sarri was furious and initially headed down the tunnel before returning just in time for extra time to end. In the shootout, Kepa made only one save from Leroy Sane as Raheem Sterling completed the shootout victory to defend City's title and keep the team in contention for a quadruple.
"In no moment was it my intention to disobey, or anything like that with the boss," Kepa said. "Just that it was misunderstood because I had been attended to by the medics twice, and he thought that I wasn't in condition to continue.
"It was two or three minutes of confusion until the medics got to the bench, and they explained everything well." After collecting his runners-up medal, Sarri sought to diffuse the controversy. "It was a big misunderstanding," Sarri said. "I understood the goalkeeper had cramp and for me he was unable to go to penalties but the problem was not cramp so he was able to go to penalties."
Not that Sarri wants to see a repeat. "Kepa was right but in the wrong way," Sarri said. "He was right for the motivation but not for the conduct." Even Kepa realized the incident was damaging for the club's reputation as images flashed around the world.
"I understand that on television, on social media, they're talking about this but I am here to explain it, to say that it wasn't my intention to go against the manager," Kepa said. "We have spoken now, and I was only trying to say 'I'm fine.' He thought I wasn't fine. It was in tense moments, with a lot happening."
The insubordination exposes the player power that has appeared to often cause problems for Chelsea managers. It leaves the 60-year-old Sarri without a trophy in his career and Kepa's defiance adds to the manager's problems with Chelsea down to sixth in the Premier League.
The incident distracted attention from how Sarri had set up his team to successfully thwart City two weeks after a 6-0 loss in the Premier League. "Today the players played exactly the match we prepared," Sarri said. "I think I am fully in control of this situation. ... We conceded nothing to the best team in Europe."
Former Chelsea manager Jose Mourinho said seeing Sarri undercut by Kepa made him "really sad." "I don't like that he leaves his coach and the assistant coach in a situation of great fragility," Mourinho said while covering the match in Spain for the internet streaming service DAZN.
Mourinho was fired by Chelsea in 2015 over "palpable discord" with his players. "Luckily I never had to go through this," Mourinho said of Kepa's onfield behavior. "The goalkeeper wants to show his personality, his confidence, wants to show that he is there and wants to be at the shootout and make saves — and I like that."
The episode also took the focus off Pep Guardiola winning his third major trophy in three seasons at City. City did lose top spot in the Premier League on Sunday after Liverpool drew 0-0 at Manchester United. But City is only a point behind Liverpool and the Abu Dhabi-owned team remains in contention for the Champions League and FA Cup as well.
"The only problem is we will miss a lot of important players for the next few weeks," Guardiola said. "Being in four competitions is so demanding, so tough. We don't know where we're going to arrive. "(Aymeric) Laporte, Fernandinho are injured, but it's much better of course when you win."
And win calmly — without a flashpoint like Kepa defying his manager. "I've never seen it (before)," City captain Vincent Kompany said. "I wish I could do it every now and then when I don't want to get subbed off."
More AP soccer: https://apnews.com/apf-Soccer and https://twitter.com/AP_Sports