Vale suffered their first defeat of the season in Sky Bet League Two on Saturday afternoon as Wycombe Wanderers ran out 3-2 victors at Vale Park.
A brace from Adebayo Akinfenwa and a strike from Paris Cowan-Hall handed the Chairboys a three-goal lead at the break, but Vale did give the away side a scare late on.
Dan Turner and Ben Whitfield both found the net for Michael Brown's side, but the manager was left disappointed with his team's slow start.
He said: "It's deeply frustrating when you start the game as we did. They had a big, strong boy up front and he got the better of us.
"The first goal was a foul, but ultimately it gave them a start. The second and third goals, there are no excuses on our part, we should have defended them.
"When you give someone, at any level, a three-goal head start you're always up against it."
Brown admits that he aired his views strongly during the half-time break and he was pleased with the reaction he got from his players during the second 45 minutes.
He said: "They certainly knew my feelings from what I said, put it that way.
"We came back out and the substitutes reacted well, changed it slightly and we managed to get a couple of late goals which gave us half a chance."
Speaking about the goals Vale conceded, the manager said the players had 'been working on them all week'.
He added: "We worked on the first goal, we knew what they did and we practiced defending that only yesterday. He (Adebayo Akinfenwa) has just nudged Kaysy (Antony Kay), he said he fouled him but it has just crept in.
"The second and third goals were disappointing - one long ball and a set piece. It was a poor performance, we had worked all week doing the right things, but when you start like that you're struggling."