On 8 April 2014, Kubalík returned to HC Plzeň on a two-year contract.[4] On 25 August 2017, Kubalík signed a three-year contract with HC Ambrì-Piotta of the National League (NL).[5] He split the 2017–18 season between HC Ambrì-Piotta and HC Plzeň (while on loan).
On 29 May 2019, the Blackhawks signed Kubalík to a one-year, $925,000 contract.[8] On 10 October 2019, Kubalík scored his first career NHL goal in a 5–4 loss to the San Jose Sharks.[9] In his first season he played on a line with Jonathan Toews and Brandon Saad.[10] On 27 February 2020, Kubalík recorded his first career NHL hat-trick in a 5–2 victory over the Tampa Bay Lightning. All 3 of Kubalík's goals came in the third period.[11] He finished the regular season with 30 goals and 16 assists for 46 points in 68 games. On 15 July 2020, Kubalík was named a finalist for the Calder Memorial Trophy (alongside Quinn Hughes and Cale Makar), which is awarded to the league's best first-year player.[12] He was named to the NHL's All-Rookie Team.[13]
The Blackhawks met the Edmonton Oilers in the 2020 Qualifying Round.[14] In Game 1 of the series, Kubalík recorded 2 goals and 3 assists in a 6–4 win. His 5 points were the most scored in an NHL postseason debut in league history.[15] Kubalík also scored the game winner in Game 4 to eliminate the Oilers.[16] In the following series versus the top-seeded Vegas Golden Knights, Kubalík was held to just two points as the Blackhawks were eliminated in five games.[17] Following that first season, Kubalík's production declined as Saad left the team, and Toews missed the season. His second season was marked with only 17 goals and then his final season in Chicago, 15 goals.[10]
Detroit Red Wings
As an impending restricted free agent following the conclusion of his contract on completion of the 2021–22 season, Kubalík was not tendered a qualifying offer by the rebuilding Blackhawks, and was released to free agency on 12 July 2022.[18] On the opening day of free agency on 13 July, Kubalík signed a two-year, $5 million contract with the Detroit Red Wings.[19][20] Kubalík hoped for a fresh start with the Red Wings, after struggling in his final year with the Blackhawks.[10] In his first season with the Red Wings, Kubalík registered 20 goals and 45 points in 81 games.[21] He scored against his former team, the Blackhawks, on 9 March 2023 in a 4–3 win.[22]
Ottawa Senators
On 9 July 2023 Kubalík was traded to the Ottawa Senators, along with Donovan Sebrango, a conditional first-round pick in 2024 and a fourth-round pick in 2024, in exchange for Alex DeBrincat.[23]