Port Vale manager Micky Adams felt his rookie defenders were taught a valuable lesson by Bradford.
Carl McHugh's injury-time header denied Vale a battling point at Valley Parade as the Bantams edged to a 1-0 victory.
However, Adams felt his players could take something from the disappointment.
He said: "It was a cracking game. I have told our two young centre-halves they won't have a harder game than that in their careers. It started from the first whistle and although we rode our luck at times, we created some good chances ourselves.
"It is disappointing not to come away with a point because a lot of our players put their bodies on the line. Bradford were a wounded animal and we stood up to them well. We competed until the second minute of injury time when someone switched off and it's in the back of the net. There's a valuable lesson there.
Adams made no excuse for adopting a more defensive approach, and added: "We've been conceding too many goals and we had to do something to stop that. I thought we were much tighter at the back."