Dennis Greene believes Courtney Wildin can come back stronger following his eighth-minute substitution.
The defender was replaced by Herve Pepe-Ngoma in the early exchanges of today’s 3-3 friendly draw at Stamford.
This lead to a lively exchange between manager and player on the touchline, before Wildin came back out for the second half.
“Basically, we’ve gone three at the back, Courtney on the left hand side,” Greene explained.
“His first touch too relaxed, got robbed. Next one, robbed, next one give it away.
“Then they put a cross in and he didn’t get there.
“I told him to play on the right and let the other lad go in there, he wouldn’t budge, so off you come.”
Being hauled off so early may be a horrible feeling for the young defender, but Greene hopes it will be character building.
He added: “I wanted to see his reaction. I’m the manager of the team and if they don’t so as I say then they’re off.
“He’ll learn from that.”
Callum Chippendale netted all three of United’s goals, and Greene says those strikes - two from a lesser-known midfield slot - have done his hopes of being a regular starter no harm.
“He can play out wide or as a number 10. He played number 10 then middle of midfield,” Greene said.
“He showed real qualities and two good finishes - he’s done himself no harm.”
United are now hoping to get injured Joe Burgess, Jay Rollins and Nat Brown fit in time for the season opener on August 6.
Greene suiggested an additional friendly may need to be arranged to give them vital minutes.
He added: “I’m hoping they’ll be available for at least Gateshead, you want them ready for the start of the season.
“But I can’t see Rollins, Burgess, Nat Brown ready - I don’t know.
“They’ll probably be fit for the first game and it’ll be a gamble if I play them.
“We might arrange a couple of friendlies, 21 games, and play them to get some minutes under their belts.”