McDonald was loaned to AHL Lehigh Valley on Saturday.
McDonald appeared in five games for the Flyers while Cam York (upper body) and Rasmus Ristolainen (hand) missed time due to injuries. With York back in action, McDonald became the odd man out for the team's left-shot defensemen. Overall, the 24-year-old blueliner posted a minus-2 rating, 10 PIM, three shots on net, 22 hits and six blocked shots during his NHL stint. He'll likely be a relevant injury call-up for the Flyers this season if he's needed at a later point.