Tatar fit right in with the Canadiens upon his arrival in Montreal from the Vegas Golden Knights in the Max Pacioretty trade in September 2018. He set NHL career highs in assists (33) and points (58) in his first season in Montreal.

Tatar appeared on track for a fourth straight 20-goal season with the Detroit Red Wings in 2017-18 when he was traded to the Golden Knights for three draft picks on Feb. 26, 2018.

The trade gave Vegas a player who had averaged more than 23 goals during his first four full seasons with the Red Wings.

The Red Wings selected Tatar in the second round (No. 60) of the 2009 NHL Draft, and he spent most of the next three seasons with Grand Rapids, their American Hockey League affiliate. In his first three seasons in the organization he appeared in nine NHL games, all in 2010-11, and scored one goal.

But Tatar continued to plug away in the minors, improving his point total in each of the first three seasons with Grand Rapids and playing a huge role in the run to the 2013 Calder Cup championship. Joining Grand Rapids after the Red Wings had been eliminated from the Stanley Cup Playoffs, Tatar went on a scoring tear, finishing with 21 points (16 goals, five assists) in 24 games as Grand Rapids defeated Syracuse in six games in the Calder Cup Final. Tatar had a goal in the 5-2 title-clinching victory.

Tatar made the Red Wings roster in 2013-14 and earned a new contract by finishing with 39 points (19 goals, 20 assists) in 73 games. Seasons of 29, 21 and 25 goals followed, and he had 16 goals in 62 games before being traded to the Golden Knights.

The native of Ilava, Slovakia, has been a mainstay internationally for his country, participating in two IIHF World Junior Championships, the 2014 Sochi Olympics and four IIHF World Championships. Tatar was the youngest player on Slovakia's roster at the 2012 World Championship in Finland, but contributed five points to help Slovakia win the silver medal.

Tatar signed a one-year contract with the Colorado Avalanche on Sept. 12, 2023. He was plus-41 in 82 regular-season games for the New Jersey Devils in 2022-23 and one goal in 12 Stanley Cup Playoff games, the second player in Devils/Colorado Rockies/Kansas City Scouts history to score at least 20 goals and have a plus-minus rating of at least plus-40 (Patrik Elias, 40 goals and plus-45 in 2000-01).

The Avalanche traded Tatar to the Seattle Kraken on Dec. 15, 2023, for a fifth-round pick in the 2024 NHL Draft.

Tatar signed a one-year, $1.8 million contract with the New Jersey Devils on July 1, 2024.