Well, this isn't good.
This leaves questions about what the Red Bulls do to compensate for McCarty's absence (for this weekend, anyway). Somewhat thankfully, they've already been playing with two central midfielders wide, with Jonny Steele and Eric Alexander. Either one of them can move centrally, freeing up a spot out wide for a player like Lloyd Sam or Ruben Bover.
As the above report notes, Ian Christianson, who was brought in as cover for McCarty as the team was shallow at the defensive midfielder position, is out with a foot injury.