Atletico Madrid coach Diego Simeone concedes that his behaviour needs to improve following his dismissal in the first leg of his side's Europa League semi-final with Arsenal. Simeone was sent to the stands in the early stages of an eventful game at Emirates Stadium on Thursday, having complained to officials following the red card shown to right-back Sime Vrsaljko in the 10th minute. UEFA has charged the former Argentina international with insulting a match official and improper conduct, with a disciplinary panel to judge the case on May 4, the day after the second leg in Madrid. Speaking at his pre-match press conference ahead of Sunday's LaLiga visit to Deportivo Alaves, Simeone pledged to improve his behaviour. "I don't feel good about that," he said. "I understand that this can happen because things on the field go really fast. ¡Hoy es un día muy especial para nuestro entrenador! ¡Es el cumpleaños de Diego Pablo @Simeone! ¡Muchas felicidades! #AúpaAtleti pic.twitter.com/PYtCpZ9phN — Atlético de Madrid (@Atleti) April 28, 2018 "I know I have to improve myself in that aspect. I can't say anything - there's no excuse. "When you are kicked out you can't say anything or justify anything, there's no excuses." UEFA also charged Atletico for their fans throwing objects during the game, while Arsenal could be punished for their supporters setting off fireworks.