Koscielny, 31, was sent off during Arsenal's 3-1 Premier League win against Everton on Sunday following a reckless tackle on Enner Valencia.

But while an appeal against the dismissal was lodged by Arsenal, the FA has announced that the France international will be suspended for three games -- the FA Cup final and the first two Premier League matches of next season.

"Laurent Koscielny will serve a three-match suspension with immediate effect after a claim of wrongful dismissal was unsuccessful," an FA statement read.

"The Arsenal defender was sent off for serious foul play during the game against Everton on Sunday [21 May 2017]. An Independent Regulatory Commission heard the case today [Tuesday 23 May 2017]."

The news comes as a huge blow to Arsenal, who are hoping to salvage a disappointing season -- that saw them finish fifth in the Premier League and miss out on Champions League qualification -- with FA Cup success.

Arsenal look to already be without fellow centre-back Gabriel Paulista, who was forced off against Everton with a knee injury, for Saturday's game, while Shkodran Mustafi is also a doubt.

Arsenal captain Per Mertesacker may be called upon by manager Arsene Wenger, though he has made only one appearance all season -- coming off the bench against Everton -- following fitness issues.

Wenger said after the Everton game that Koscielny's red card "was harsh, but we have to accept the decision."