Heskey, 31, has been considering his future at Villa due to his lack of first-team action.
But he came off the bench to score his first goal of the season at Turf Moor. And Milner said: "I'm delighted for him because he deserves it and hopefully he has now given the manager a few selection problems.
"The ball was there for him to get in there and get his head onto and do what good strikers do.
"It just shows the strength that we have in the squad now that we can bring the likes of Emile Heskey on and change the game."