Phelan told manutd.com: "Gibbo has been with us a while and floated in and out of the squad. But this season he's made an adjustment in mental and physical terms and seems at home within the first-team group.
"His first goal [against Southampton] will have done him the world of good. All the hard work you've put in and all your dreams and aspirations together in that one instant. Once you've done it, you want to do it again and you can see that desire in Darron."