The deal is only pending a medical, which is expected to be completed soon. Grandsir will be signed using Targeted Allocation Money, preserving the Galaxy's lone open Designated Player spot.
Grandsir, 24, started his career in his hometown Evreux before breaking through as a professional with Troyes in 2016. He scored six goals in 77 appearances with Troyes before making the move to Monaco in 2018, but spent most of the next two seasons on loan with RC Strasbourg and Stade Brest 29.
In total, Grandsir has scored 12 goals in 131 first-team appearances. Internationally, Grandsir made four appearances with the France U21 side.
Grandsir would join a winger group including homegrowns Efra Alvarez and Cameron Dunbar. The club currently have one open DP spot.
Head coach Greg Vanney took over this winter at the club, who have begun making some changes to the roster. Irish international center back Derrick Williams, left back Jorge Villafana and goalkeeper Jonathan Bond highlight the additions thus far.