Leno's error led to Jorginho scoring the equalising goal for Chelsea - who were a goal down due to Pierre-Emerick Aubameyang's strike in the 13th minute.
Mikel Arteta has promised to motivate Bernd Leno after the goalkeeper's error in Arsenal's 2-1 loss to Chelsea on Sunday.
Leno's mistake led to Jorginho scoring the equalising goal for Chelsea - who were a goal down due to Pierre-Emerick Aubameyang's header in the 13th minute. The Blues eventually won the match at the Emirates stadium as Tammy Abraham scored three minutes after Leno's blunder.
However, Arteta, who suffered his first defeat since taking charge of the Gunners, said his team must look forward to their clash against Manchester United on New Year's Day.
"He will be down, but we have to lift him," Arteta said of Leno. "He's been brilliant for this football club.
"I'm really disappointed with the result, the way we conceded and the timing. I'm pleased with lots of things, but I'm disappointed to lose.
"I thought the structure was good. We need to control those situations but they are really good in transition.
"We have to move on."
Granit Xhaka wasn't in the starting line-up that played against Chelsea yesterday, however, Arteta explained why he decided not to pick the Switzerland international.
“He [Xhaka] started to feel ill after the Bournemouth game,” the Spaniard said. “I hope he doesn’t leave in January.”