The Cincinnati Reds selected Kolozsvary in the seventh round, 197th overall, of the 2017 MLB draft,[2] and he signed with the team.[5] He made his professional debut with the rookie-level Billings Mustangs, posting a .305/.362/.411 slash in 28 games. In 2018, Kolozsvary played for the Single-A Dayton Dragons, where he hit .225/.310/.324 with 3 home runs and 27 RBI. The following season, Kolozsvary received a promotion to the High-A Daytona Tortugas, and slashed .188/.341/.321 in 79 games with the team.[6]
During the COVID-19 pandemic, which resulted in the cancellation of the 2020 minor league season, the Reds included Kolozsvary in their 60-man player pool at their alternate site, but did not see any game time in the major leagues.[7] Kolozsvary was assigned to the Double-A Chattanooga Lookouts to begin the 2021 season. In August, the Reds promoted him to the Triple-A Louisville Bats.[8] On September 20, 2021, Cincinnati selected Kolozsvary's contact and added him to the active roster,[9] but he was optioned back on September 22 without making an appearance with the Reds.[10]
Kolozsvary began the 2022 season with Chattanooga. He was selected to the 40-man roster and made his major league debut on April 20, appearing as a defensive substitute for the Reds.[11] On April 28, Kolozsvary collected his first MLB hit and RBI, lacing a double off of San Diego Padres starter and former Team USA teammate Nick Martinez.[12] On July 23, Kolozsvary hit his first career home run, a solo shot off of Junior Fernández of the St. Louis Cardinals.[13]
Baltimore Orioles
On October 14, 2022, Kolozsvary was claimed off waivers by the Baltimore Orioles.[14] On November 19, he was removed from the 40-man roster and sent outright to the Triple-A Norfolk Tides.
Kolozsvary was assigned to the Double–A Bowie Baysox to begin the 2023 season, and was quickly elevated to Triple–A Norfolk. In 20 games for Norfolk, he struggled to a .162/.250/.265 batting line with 2 home runs and 7 RBI. On June 13, 2023, Kolozsvary was selected to the major league roster after Ryan Mountcastle was placed on the injured list with vertigo.[15] He appeared as a defensive replacement for Adley Rutschman in that day's game against the Toronto Blue Jays, and was optioned to Triple–A the following day.[16] Kolozsvary was designated for assignment by the Orioles on June 14, following the promotion of Reed Garrett.[17] On June 16, he cleared waivers and elected free agency in lieu of an outright assignment.[18]
Minnesota Twins
On June 20, 2023, Kolozsvary signed a minor league contract with the Minnesota Twins.[19] He played in six games for the Triple–A St. Paul Saints, going 3–for–14 (.214) with one home run and four RBI. Kolozsvary elected free agency following the season on November 6.[20]
Boston Red Sox
On December 22, 2023, Kolozsvary signed a minor league contract with the Boston Red Sox.[21]