The Dutchman was surprisingly given a start in defence by Gordon Strachan in the Hoops Scottish Cup final win over Rangers and produced a superb performance and McDonald believes he can re-produce that fantastic form.
"I think it was his best game to date thus far," said McDonald.
"He was a demon in the air yesterday I've got to say.
"He won everything and we saw how good a defender he is yesterday, but of course its always going to be difficult for a manager to drop players who have played so well.
"So, I'm just glad it's not me having to make those decisions."