He also played in the National Hockey League (NHL) for the Toronto Maple Leafs, the organization that drafted him in the seventh round, 216th overall, in 2005, as well as the Columbus Blue Jackets, the New York Rangers, the Tampa Bay Lightning, the Florida Panthers, the Arizona Coyotes, and the Boston Bruins.

[7] As a restricted free agent at the end of the season, he initially planned to bring the Rangers to a salary arbitrator, but on 26 July 2012, he signed a two-year, $3.4 million contract with New York.

On 1 July 2014, Strålman left the Rangers organization as an unrestricted free agent and signed a five-year, $22 million contract with the Tampa Bay Lightning.

[10] After missing the last eight games of the 2015–16 season and the first two rounds of the 2016 playoffs against the Detroit Red Wings and New York Islanders, Strålman returned to the lineup in time for the third round series against the Pittsburgh Penguins, where they would fall in seven games, one win short of a second consecutive appearance in the Stanley Cup Finals (third consecutive for Strålman himself).

After five seasons with the Lightning organization, Strålman left as a free agent to sign a three-year, $16.5 million contract with the Florida Panthers on July 1, 2019.

Approaching the 2022–23 season, he initially joined the Boston Bruins training camp and pre-season on a professional tryout before agreeing to a one-year, $1 million contract on 11 October 2022.

[15] On 15 April 2017, the Swedish Ice Hockey Association invited Strålman to its roster for the 2017 IIHF World Championship.