Pardew said: "Scott has a large golf-ball-sized lump on his head from a clash with Morgan.
"He wasn't quite right at half time. I don't think he was concussed, but he felt a little bit uncomfortable.
"That actually turned out to be significant for us because (Brede) Hangeland came on and I thought he was our best player.
"He was calm, great defensively, won everything and contributed to the goal, so kind of indirectly it worked for us."