Kovar played the entirety of Saturday's 2-2 away draw at Teplice, where a double from the hosts’ forward Abdallah Gningue cancelled out Sparta Prague’s two-goal lead.
Strikes from Jakub Jankto and Tomas Cvancara had made it 2-0 to the visitors after 40 minutes, but Gningue scored in the 43rd and 83rd minutes to deny the United loanee a winning debut.
The draw leaves Sparta Prague in fourth place in the Czech First League, after eight fixtures, and Kovar will be hoping to help his side move up the table during the rest of the 2022/23 season.