Arsenal threw away a two-goal lead over Watford but Unai Emery is confident it will prove a valuable learning experience for his side.
Arsenal were architects of their own downfall in Sunday's 2-2 draw with Watford and Granit Xhaka has questioned his team-mates' character.
Watford held Arsenal to a 2-2 draw despite going 2-0 down in Quique Sanchez Flores' first match back at the club.
Mesut Ozil made his first start of the season in Sunday's draw with Watford, but he could not inspire Unai Emery's Gunners.
Arsenal boss Unai Emery picked Nicolas Pepe and Pierre-Emerick Aubameyang with Mesut Ozil tucked in behind at Watford.
Roberto Firmino "showed his class" with two assists against Newcastle United, according to Liverpool team-mate Andy Robertson.
Watford sacked Javi Gracia when he was in conversation with Unai Emery during a break in Spain.
Norwich City pulled off an upset against Manchester City, but Daniel Farke intends to be quite restrained in his celebrations.