The Italian spoke in the wake of his side's disappointing 1-1 draw at home to Verona, in which Morata had a goal unfortunately ruled out for offside, while Dybala smashed a shot against the underside of the crossbar.
Ronaldo has been absent due to his positive coronavirus test, and it was felt as his side missed other numerous chances and lacked a cutting edge.
Dybala has also been missing for most of the season through injury, and it was unclear which formation Pirlo would opt for with all of his players fit.
But Pirlo, perhaps cryptically, suggested that when Ronaldo returns he would play with either forward, but not necessarily with both.
He said: "Cristiano can play with Morata or with Dybala, depending on the characteristics. His classic position is to start slightly left and cut inside. Dybala or [Dejan] Kulusevski can do that too.
“Positions are interchangeable during a game, the important thing is to move within certain zones to create problems for the opposition defence.
"We could have done better, we have to improve but I see that the team is growing, my idea of the game is taking shape, Arthur understanding what I want from him. Obviously the players have to get used to it, we often miss the last pass but I'm optimistic."
Meanwhile Ronaldo is facing a race to be available for the Barcelona clash in the Champions League on Wednesday, with him required to provide a negative coronavirus test within 24 hours of kick-off in order to be sanctioned to play.