After three seasons with Stavanger Oilers he moved to continue his development in North America, joining major junior club the Kamloops Blazers of the Western Hockey League (WHL) for the 2016–17 season. Balcers made a seamless transition to the WHL appearing in 66 games with the Blazers, finishing with 40 goals, the most on the team.[5]
Having experienced a successful season with Blazers, he was signed to a three-year, entry-level contract with his draft team, the San Jose Sharks, on 13 July 2017.[6] After attending the Sharks 2017 training camp, he was assigned by the Sharks to begin his North American professional career with AHL affiliate, the San Jose Barracuda.[7] In the 2017–18 season, Balcers led the Barrcuda with 23 goals and 25 assists for 48 points in 67 games.[5] He was selected to represent the Barracuda at the 2018 All-Star Classic.[8]
In September 2018, Balcers was traded by the Sharks to the Ottawa Senators as part of a package of players, prospects and draft picks for Erik Karlsson.[9] Assigned to the Senators' AHL affiliate the Belleville Senators to start the season, Balcers was leading the team in goals and points when he was recalled by Ottawa in early January 2019.[10] He made his NHL debut with the Senators on 5 January 2019, against the Minnesota Wild,[11][12] and scored his first goal in the next game, on 6 January against the Carolina Hurricanes.[13]
After missing most of the 2019–20 season with an MCL injury, Balcers signed a one-year, two-way contract with the Senators in October 2020.[14] Shortly after that, he was loaned back to Stavanger until the start of the delayed 2020–21 season.[15] Balcers compiled seven goals and eight assists in just 10 games in his return with the Stavanger Oilers before returning to the Senators organization.
Approaching the conclusion of training camp, Balcers was placed on waivers by the Senators and subsequently claimed by his original club, the San Jose Sharks, on 12 January 2021.[16] He scored his first goal for the Sharks, in a 5–4 win over the St. Louis Blues on 20 February 2021.[17] On 22 July 2021, Balcers signed a two-year, $3.1 million contract with the Sharks.[18]
Following the 2021–22 season, despite having recorded career-best marks with 11 goals and 23 points through 61 regular season games, Balcers was placed on unconditional waivers by the Sharks in order to buyout the remaining season of his contract on 12 July 2022.[19] On 14 July, Balcers as a free agent agreed to a one-year, $750,000 contract with the Florida Panthers.[20] He made his Panthers debut on the opening night of the 2022–23 season, in a 3–1 victory over the New York Islanders on 13 October.[21]
Despite contributing with two goals and two assists through 14 games with the Panthers, Balcers was placed on waivers due to other roster considerations on 11 November 2022.[22] The following day on 12 November, Balcers was claimed off waivers by rival club, the Tampa Bay Lightning.[23]
After five NHL seasons, Balcers left as a free agent and was signed to a one-year contract with Swiss club, ZSC Lions of the NL, on 4 July 2023.[24]
After representing Latvia at the junior level, Balcers was selected by head coach Bob Hartley for the 2018 World Championship.[25] In his senior debut game against Norway, he scored two goals including the overtime-winning goal.[26][27] The four goals and six points he scored in eight games led the Latvian team.[5]
He represented Latvia at the 2023 IIHF World Championship where he recorded two goals and seven assists and won a bronze medal, Latvia's first-ever IIHF World Championship medal.[28]