The Spaniard, who became the world's most expensive goalkeeper when he joined Chelsea for 80 million euros in 2018, had been second-choice behind Edouard Mendy in the last two seasons.
However, he has been in outstanding form since coming back into the side following an injury to Mendy last month, starring in Chelsea's 2-0 Premier League win over Aston Villa on Sunday where he produced a series of superb saves.
"Every player needs confidence, this push, and for the goalkeepers it is even more important," Arrizabalaga told Prime Video.
"If you are playing in a row of games, it's important for your confidence and I'm playing well, I think. I need to keep going and keep working."
Kepa also impressed in Chelsea's draw at Brentford, twice denying in-form striker Ivan Toney with saves that earned praise from opposition manager Thomas Frank.
"Kepa was fantastic," Frank told Prime Video. "Every time Chelsea come here, their goalkeeper is man of the match."
Chelsea, who are fourth in the league, host fifth-placed Manchester United on Saturday.
