The Ajax coach is full of praise for the successful Barcelona coach and has stated that Guardiola has already shown that he's capable of making difficult decisions
"In the modern game, you tend to dominate if you have eight or nine players behind the ball, just like Barca. Leaving two wingers up front glued to the touchline doesn’t help an awful lot. You have to be dynamic, full of movement," De Boer said to fifa.com.
"Keeping possession of the ball seems like a silly thing to say on paper, but on grass it’s actually even more important than it sounds."
De Boer then went on to praise Guardiola for his ability to make the right choices at the right time.
"Guardiola has stuck with his approach, and has shown that he’s capable of making difficult decisions, be it with Samuel Eto’o or Zlatan Ibrahimovic. He knows what he wants and he doesn’t waver from his choices."
Barcelona defend a 2-0 lead from the first-leg against arch rivals Real Madrid when both sides lock horns in the Champions League semi-finals on Tuesday.