[5] After his success in the 2009 World Junior Championships, he returned to Calgary and made his NHL debut on 8 January 2009, in a 5–2 win against the New York Islanders.

Competing for the Rockets in the 2009 WHL playoffs, Backlund tied teammate Jamie Benn for the League lead with 13 goals in 19 games as Kelowna defeated the Calgary Hitmen in the final to win the Ed Chynoweth Cup.

[6] Backlund began the 2009–10 season with the Flames' American Hockey League (AHL) affiliate, the Abbotsford Heat.

He was expected to centre the Flames' top line between Jarome Iginla and Alex Tanguay, but suffered a broken finger in training camp that twice required surgery to repair and caused him to miss the first six weeks of the season.

[11] He then suffered a shoulder injury in a mid-February game while attempting to confront a Vancouver Canucks player he felt had injured a teammate.

He re-joined Västerås and appeared in 23 games for the team, scoring 12 goals and 30 points before returning to North America after a new deal between the NHL and its players was reached.

His performance with Västerås provided a confidence boost for Backlund, who said that he wanted to return to Calgary and "show everybody I can play way better."

In 2014–15, Backlund faltered slightly, suffering through injuries and trade rumours; however, the Flames surprisingly skyrocketed up the standings en route to their first playoff berth in six years.

However, the one goal Backlund scored was an important one, as it came in overtime of Game 3 of the Flames' second-round series against the Anaheim Ducks to give Calgary their first win past the first round in 13 years.

[16] Put on a line with free-agent acquisition Michael Frolík, Backlund enjoyed his most productive year yet in 2015–16, passing the 20-goal and 40-point plateaus for the first time in his career.

While contributing significantly in the offensive zone, Backlund also established himself as a defensive catalyst, forming a tag-team on the penalty kill with Frolík; together, the two of them combined for five short-handed goals in the season.

[17] On 27 September 2023, Backlund signed a two-year contract extension with the Flames, and was named the 21st captain in franchise history.

After being eliminated in the second round of the AHL playoffs in 2010, Backlund was invited to play for Sweden's men's team at the World Championships, accepting the offer.

Despite being left off the initial roster, Backlund was invited to the 2016 World Cup of Hockey as a replacement for injured Henrik Zetterberg on 1 September.