The Kings will retain 25% of Forbort's salary, according to Sportsnet's Ryan Leslie. If the Flames make the Western Conference Final this spring and the defenseman plays in half the games, or if he re-signs this offseason, the pick becomes a third-rounder in 2022, per Wes Gilbertson of Postmedia.
Chicago will receive the earlier of Calgary's two third-round picks in 2020.
Flames General manager Brad Treliving was hoping to improve his team's back end ahead of the deadline. The Flames currently occupy the Western Conference's first wild-card spot despite being the only club with a negative goal differential while holding a playoff position.
After recording 60 points last season, Gustafsson's output has cooled somewhat in 2019-20. He's amassed 26 points in 59 games this year.
Forbort, meanwhile, has missed most of the current campaign due to a back injury. He's a steady third-pairing blue-liner when healthy.