Well, I think the Siggy injury means both a golden opportunity for Klaassen and BFS. Klaassen is now the best fit in that role if we are going to play a lineup like last weeks and one of only two players(Vlasic) we can play there without putting a more defensive team on the field. And BFS has an excuse to play him now with the injury, though I suspect for more defensive games he will just drop Gana back in and push Davies or Rooney up.
As for position, I do agree in that I think hes actually a box-to-box. He played some no.10 last year, but prior to that, and for much of his success he actually played as a box-to-box.