Adkins - a former goalkeeper himself - also had words of comfort for McCarthy as the 23-year-old prepares to link up with the senior England squad for the first time.
He said: "Alex is still a young goalkeeper. It's all a good learning experience. He just needed to clear the football, didn't he? It was a poor execution and that's life.
"The big thing I've noticed with Alex is if he does make a mistake he can quickly forget it, which is important in a goalkeeper.
"It's how quickly you can move on and Alex has done that.
"He is going to develop into a really good goalkeeper."