Usually hockey players must hit the ice to make history. Not so for Johnson.

When the St. Louis Blues selected him with the No. 1 pick in the 2006 NHL Draft, the Bloomington, Minn., native became the first American-born defenseman chosen first directly from USA Hockey's National Team Development Program. He was also the second United States-born defenseman to be the top pick, following Bryan Berard in 1995.

A mobile skater with a big shot and a 6-foot-4, 230-pound frame, Johnson made his mark as soon as he joined the Blues following one season with the University of Minnesota.

The 19-year-old rookie assisted on a Keith Tkachuk goal for his first NHL point in the 2007-08 season opener. In his second game, Johnson scored on the power play for his first NHL goal as the Blues beat the Los Angeles Kings 5-3.

Johnson led all Blues defensemen in scoring with 33 points that season and finished 12th in voting for the Calder Trophy, awarded to the NHL's top rookie.

A golf cart accident sidelined Johnson for all of 2008-09 with torn knee ligaments, but he returned to form in 2009-10, leading St. Louis defensemen in goals (10), assists (29), points (39), shots (186) and power-play goals (6).

The Colorado Avalanche acquired Johnson as part of a four-player trade on Feb. 19, 2011. He scored his first goal with the Avalanche against the Blues in his second game with his new team, helping Colorado to a 4-3 win that snapped a 10-game losing streak. Johnson finished the season averaging 24:33 of ice time per game while scoring three goals and 10 points.

Johnson made his Stanley Cup Playoff debut April 17, 2014 in Colorado's first-round series with the Minnesota Wild. He led the Avalanche with 30:22 of ice time and assisted on the game-tying goal in what would be a 5-4 overtime win in Game 1, and added his first playoff goal as the Avalanche lost Game 7.

Johnson earned his first All-Star Game selection in 2014-15, though he did not play because of a knee injury that sidelined him for the final 34 games of the season. Before the 2015-16 season, Colorado signed Johnson to a seven-year contract extension through the 2022-23 season.

The investment paid off when Johnson became the first Avalanche player to receive the Stanley Cup from captain Gabriel Landeskog after they defeated the Tampa Bay Lightning 2-1 in Game 6 of the Stanley Cup Final. It was Johnson's first NHL championship of his 14-season career.

Johnson played the 900th game of his NHL career, a 4-1 win against the Calgary Flames on Jan. 18, 2023. He was at the time the longest tenured member of the Avalanche and any of Denver's four major sports teams. His career in Denver ended when he signed a one-year, $3.25 million contract with the Buffalo Sabres on July 1, 2023. He scored three goals in 50 games before he was traded to the Philadelphia Flyers on March 8, 2024, for a fourth-round pick in the 2024 NHL Draft.

Johnson signed a one-year, $1 million contract to stay with the Flyers on July 1, 2024. He played 12:51 in his 1,000th NHL game, a 5-2 Flyers win against the Buffalo Sabres in Philadelphia on Nov. 16.

He returned to the Avalanche when the Flyers traded him to Colorado on March 7, 2025, and retired from the NHL after 17 seasons Oct. 1. Johnson played 14 seasons with the Avalanche. Only Adam Foote (17) played more among Avalanche/Quebec Nordiques defensemen and only Foote and Joe Sakic (20) among all Colorado/Quebec skaters.