Foster made an immediate impact in his first professional season with the Switchbacks in 2022, earning 16 starts across 25 appearances and logging over 1,500 minutes. He contributed 32 clearances, won 30 of 39 tackles, and maintained a 77.9% passing accuracy.
He spent the 2023 and 2024 seasons with MLS NEXT Pro side FC Cincinnati II, making 39 appearances and continuing as a key starter. Foster made his MLS debut on June 29, 2024, against FC Dallas and scored his first goal for the team in the 2024 CONCACAF Champions Cup against Cavalier FC. He then returned to the Switchbacks ahead of the 2025 season.
