[5] On 20 December 2021, Čvančara signed a multi-year contract with Czech giants Sparta Prague,[6] playing 15 league matches and scored seven goals.

[citation needed] On 28 January, after a fight with Sigma Olomouc defender Tomáš Vraštil, Čvančara suffered a concussion and was briefly unconscious.

[11] In a 5–1 victory against VFB Stuttgart on 29 July, Čvančara scored an excellent hat-trick with a freekick to complete it, leading Borussia Mönchengladbach to win the pre-season tournament.

[12] On 11 August 2023, Čvančara scored his first two goals and provided an assist on his official debut for the club in the first round of the 2023-24 DFB-Pokal against TuS Bersenbrück.

[14] On 24 March 2023, Čvančara made his debut and scored his first goal for the Czech Republic national team in a 3–1 victory against Poland during the Euro 2024 qualifiers.