The goalkeeper refused to come off against Man City late in extra-time, waving off his manager, who was trying to put back-up Willy Caballero in the match.
Kepa ended up staying on the pitch and took part in a penalty shootout after 120 scoreless minutes, with City emerging victorious.
Though Sarri was visibly furious on the pitch, he and the goalkeeper tried to calm things down after the game, insisting the incident was only a misunderstanding.
But Sarri did end up suspending the goalkeeper for Chelsea's next match, which came against Tottenham.
The Blues won that match 2-0 and have won their two subsequent games, making it four wins from five in all competitions.
Their lone blemish was the shootout defeat to City, but that came just two weeks after Chelsea were destroyed 6-0 at the hands of City.
Sarri has hailed his team's effort in the Carabao Cup final, despite not lifting the trophy.
"As you know, for me, it was really very important the performance in the final against Manchester City," Sarri said.
"Two weeks before that match we lost 6-0 in Manchester. A fortnight later, the players were able to play at the same level as them, so that was important for our confidence."
The Italian even went as far as to say that the incident with Kepa, which many saw as evidence Sarri's players were tuning him out, was a net positive for his team.
"In the end, the Kepa situation was a good thing for our group, too," Sarri said.
"In the last five matches, we won four matches and drew against Manchester City. In five matches, we conceded only one goal. So we are improving in consistency.
"But we have to be careful. We had a long period of good results in the past and then, suddenly, two weeks of disaster. So we have to be careful."
Chelsea look to make it four wins in a row when they face Wolves in the Premier League on Sunday.