FC Cincinnati Markanich was selected by
FC Cincinnati in the
2022 MLS SuperDraft. He was chosen as the 2nd pick in the 2nd round of the draft, or the 30th overall pick. He was signed to a contract for the 2022 season (with options through the 2025 season) on February 21, 2022. He started in FC Cincinnati's first match of the season on February 26. Markanich was released by Cincinnati following their 2022 season.
Charleston Battery On February 16, 2023, Markanich signed with
USL Championship side
Charleston Battery following a successful trial. Markanich was among the USL Championship's top attackers in 2023. He was a five-time Team of the Week selection, the Week 15 Player of the Week and a Player of the Month nominee in June. Nick tallied 13 goals and four assists in 36 matches across all competitions, finding the back of the net in the regular season, playoffs and
Lamar Hunt U.S. Open Cup. Among Nick's most memorable goals included match-winners in the Open Cup Third Round against
Charlotte Independence and in the regular season finale against
Birmingham Legion FC, and his first-time strike in the
USL Championship Final. He additionally scored braces on the road against
Hartford Athletic and at home against
Loudoun United. Markanich scored twice during the
2023 USL Championship Playoffs, including in the league final. Markanich got off to a fast start and was the Championship's top scorer after the first months of play, scoring 11 goals in nine matches. This included a four-goal performance on April 27 against
Las Vegas Lights FC, in which he scored a hat trick in the first half, the first of his professional career. His four goals and one assist performance was only the second on record in the USL Championship era, and the first Battery player with a four-goal game in Championship. At the end of April, he was the top goalscorer of all the American domestic leagues, two goals ahead of
Lionel Messi's nine with
Inter Miami CF. Markanich was a nine-time Team of the Week selection and four-time Player of the Week (Week 6, 8, 18 and 25) winner through late-August. After scoring 15 goals in 18 games, Markanich became the fifth-fastest to reach 15 goals in a season in USL Championship history. Markanich scored his second hat trick of the season on August 24 against
Orange County SC, bringing his total to 24 goals and one shy of the league's single-season record. Markanich and teammate
MD Myers formed a formidable striker partnership for the Battery, earning them the nickname "
M&M Boys", as they led the USLC in combined goals and goal contributions (goals + assists) through late August. On September 7, Markanich scored his 25th goal of the year to tie the Championship's single-season record. On September 21, Markanich broke the USL Championship single-season scoring record with his 26th and 27th goals of the season on the same night against the Tampa Bay Rowdies. Markanich also tied the Battery's all-time single-season scoring record by matching
Paul Conway's mark of 27 scored in 2001 (all competitions). Markanich broke Conway's record in the next game, converting from the penalty spot on October 5 against Detroit City FC. Markanich was crowned winner of the USL Championship Golden Boot with 28 goals scored in the regular season. Markanich also ended the year as the top goalscorer across all domestic leagues in the United States, ahead of the likes of
Christian Benteke,
Lionel Messi and
Luis Suarez in MLS. He scored two more goals in the USL Championship Playoffs as the Battery reached the Eastern Conference Final for a second consecutive year. His 30 goals set the club's new single-season scoring record. After the season, Markanich won USL Championship Player of the Year and garnered All-League First Team honors. Markanich was a near-unanimous pick for Player of the Year and was the first Battery player to win the award since
Lamar Neagle in 2010.
Castellón On August 30, 2024, Markanich agreed to a contract with Spanish
Segunda División side
CD Castellón, effective as of January 1.
Loan to Houston Dynamo On January 20, 2026, Markanich returned to the United States after agreeing to a one-year loan deal with
Houston Dynamo of the
Major League Soccer. == International career ==