Dwyer had participated in the Lions' first preseason game, according to Poe, but was on the bench for the second on Wednesday.
The former star of Orlando's USL era has struggled to remain healthy throughout his return from Sporting Kansas City midway through the 2017 season. He made 27 appearances last season — 16 starts — while scoring seven goals and adding four assists.
If healthy, the 29-year-old Dwyer remains the most obvious candidate to play the No. 9 role for new manager Oscar Pareja, though Tesho Akindele edged him with 10 goals last season. Nani led the team with 12 from an advanced midfield role.