Man City kid McGivern backed to bounce back from international setback
Worthington said: "I thought it was a bit harsh to send the youngster off in the circumstances as the match was a friendly.
"The first challenge was enthusiasm, that's all, and no-one was hurt. But the referee has made a decision and we have to live with that.
"I am just disappointed for the boy because he did extremely well. He will remember what happened for the rest of his life.
"On the one hand he was delighted to make his senior debut but on the other hand he is hugely disappointed with the decision.
"But that is part of being a professional player. Ryan has an old head on young shoulders so he will deal with this very quickly."