"It's always about a squad - in the first half of the season we didn't really have any injuries, so we had plenty of players to put on the bench," Barry told Villa's website.
"But Marlon deserves a lot of credit - probably more than he got - because he pumped the players at half-time in the dressing room and got the crowd going.
"His workrate lifted everyone, and I'm sure John with his goals appreciated all the work Marlon did for him.
"Marlon was half-thinking he might have started against Newcastle with Gabby being out, but he had to wait until half-time.
"You could tell he was desperate to prove a point, and I think he did and he's now in the manager's mind.
"Marlon's been an asset all season - he's kept working hard and he's had to remain patient. But he's been around the game long enough to know you have to do that sometimes."