White, 23, was drafted in the fourth round of the 2022 draft by Dallas and has yet to make his NHL debut.
The right-shot D-man has spent all of the 2025-26 with the AHL’s Texas Stars. In 23 games, he has three goals, two assists and a minus-6 rating.
A native of Brockville, Ont., White played his junior hockey with the Hamilton Bulldogs and Peterborough Petes before making the jump to the AHL in 2023-24.
White will be assigned to Calgary’s AHL affiliate.
Poirier, meanwhile, leaves the Flames after spending five years in their development system.
Calgary took the 23-year-old with its third-round pick in the 2020 draft.
Poirier has also yet to make his NHL debut, and has spent the past four seasons in the AHL with the Calgary Wranglers. This year, the left-shot defenceman has one goal, five assists and a minus-18 rating in 35 games.
After trading Rasmus Andersson in mid-January, Calgary GM Craig Conroy said during an appearance on Flames Talk that the club was looking to bolster its pool of young right-handed defencemen — something that it achieves with Monday’s deal for White.
