Edouard Mendy has long been <a href="https://www.thenationalnews.com/tags/chelsea-fc/" target="_blank">Chelsea</a>'s No 1 goalkeeper but he will be feeling the pressure this week after an embarrassing error during the <a href="https://www.thenationalnews.com/sport/football/2022/08/21/thomas-tuchels-selection-gamble-backfires-as-leeds-run-riot-against-chelsea/" target="_blank">defeat to Leeds United at the weekend</a>. Mendy's costly mistake was the catalyst for Chelsea's 3-0 defeat at Elland Road as Brenden Aaronson capitalised after the Senegalese goalkeeper took too long in possession. Mendy made a mess of collecting a back pass from Thiago Silva and was then dispossessed by Aaronson, who was free to walk the ball home. Rodrigo then doubled Leeds' advantage before half time. Jack Harrison completed Leeds' first win over Chelsea since 2002 and their biggest against their rivals since 1995. Thomas Tuchel's team have taken four points from their first three games and the manager said Mendy knew more than anyone how costly his error was. "He knows himself. With these kind of mistakes I don't think it is necessary to speak a lot," he said. "He knows himself. This has nothing to do with protection, everyone in the world sees that mistake, it is a huge mistake in a crucial time of the match and it does not help. "He is the one who is the most disappointed, but it has cost us a lot today." Adding to Chelsea's misery, defender Kalidou Koulibaly was sent off for a second booking after tripping Joe Gelhardt in the 84th minute. The Blues' woes meant the spotlight was on a couple of names during their training session at Stamford Bridge. Kepa Arrizabalaga was put through his paces during training with some speculation over whether he should start Saturday's league match at home to Leicester City. There was some good news, however. Croatia midfielder Mateo Kovacic, who has been struggling with a knee problem, took part in the training session.