The Falcons said in a statement that the 26-year-old is stable and alert after being taken to a local hospital.
Adirondack defenceman Brandon Manning was assessed a two-minute penalty for boarding on the play.
MacLeod, a native of Coquitlam, B.C., picked up an assist on Ryan Craig's power-play goal in the first period.
The game was suspended in the second period with Adirondack leading Springfield 2-1. No makeup date has been announced.
MacLeod has four goals and seven assists in 20 games with the Falcons this season.