On 18 March 2021, Kúdela was accused of racially abusing Rangers midfielder Glen Kamara during a Europa League Round of 16 match. Kúdela denied the accusation and claimed he was assaulted by Kamara in the tunnel after the match, and the club lodged a criminal complaint while criticising Rangers' handling of the situation. On 14 April, he was officially found guilty of racial abuse by UEFA and was banned for ten UEFA matches, ruling him out of playing any game in the upcoming Euro 2020 championship; Kamara meanwhile was handed a three-match ban for assaulting Kúdela in the tunnel after the game. Kúdela appealed against his ban, but the appeal was rejected on 26 May 2021.