Maybe it's to help deal with Doughty, he's their biggest threat by far and perhaps Rigg is more trusted to do a defensive job on him.
If we're going down that route you may as well play Browne on the right side of midfield.
Our wingers have been playing narrow but that's dangerous with them wanting to get wide quickly and cross the ball. I'm expecting dozens of long diagonals from them tonight so our full backs will need to restrict their forward runs.
I honestly don't think midfield will be the place to try to play football, do that in the final third.