Jonny Evans admits Manchester United's emerging youngsters have shocked him into action.
The Ulsterman knows he faces a battle to keep his pace in Sir Alex Ferguson's plans.
"It is weird," he said.
"It is hard to believe Phil Jones is only 19. Chris Smalling is 21. David de Gea is 20. We have the Da Silva brothers.
"The average age against Tottenham was 23. I was just over on months. It has given the young players an incentive to step up to the mark.
"You cannot be a kid anymore and sit back and let things happen. You have to stamp your authority on the team."
