She won a bronze medal in the 4 × 5 km relay event together with Lina Andersson, Britta Norgren and Charlotte Kalla.

Haag's best individual World Cup finish is a third place in a 10 km event 21 November 2009.

Three days later, on 22 February, she won another silver medal, in the team sprint together with Charlotte Kalla.

At the Sochi 2014 Winter Olympics Haag in the 4 × 5 km relay, 3rd stage, won gold.

[4] Haag married fellow Swedish sprint specialist Emil Jönsson in 2018.