MacDonald brushed off a first-half knock to score a superb free-kick and penalty double that earned the Ton a valuable 2-2 draw with promotion rivals Partick Thistle, a result that keeps the Greenock side eight points clear at the top of the Irn-Bru First Division.
Morton boss Moore said: "He took a knock on his knee and we asked him if he wanted to come off but he said he wanted to stay on.
"We made the decision to get big Peter (Weatherson) up there because he is more of a target man than Colin (McMenamin) and we wanted to get balls in the air and feed off the second balls.
"Peaso was unlucky with the free-kick in the first half but it was a great strike for his goal going into the bottom corner.
"I don't know why he took the penalty because Michael Tidser was meant to take them.
"However, he said he had a sore foot. I don't know if that was him just bottling out of it or not.
"We had confidence in Peaso, though. He strikes a good ball.
"He missed the last one and that was a worry but it was good to see it going in."