The club has listed McDonald as week-to-week with the injury. In addition, Armstrong announced that forward Alexander Steen is considered day-to-day with an upper-body injury.
Both players were injured during practice on Tuesday while the team was participating in the "battle" drill. The exercise involves separating two goals 30-feet apart and having the players engage in a mini-scrimmage of sorts. Steen was injured during a puck battle when he fell on his shoulder, according to a report by the Jeremy Rutherford of the St. Louis Post-Dispatch.
Moments later, McDonald collided with Vladimir Sobotka and reportedly writhed on the ice in pain. He required help to the bench and apparently was unable put pressure on the leg.