Glover has won eight matches since becoming Vale manager in October
Dean Glover defended his Port Vale team after their defeat at Brentford, but admitted he cannot continue using their age as an excuse for failure.
The 2-0 defeat at Griffin Park means Vale have not gone more than two games unbeaten for almost a year.
Glover told BBC Radio Stoke: "I'm trying to protect them but I can't keep accepting performances like that.
"We've got a young side, but it's time for them to grow up and become men. We've got to compete more than we are."
Glover added: "If my players have got a bit of pride and passion in wearing that shirt, we've got a decent team who are going to compete. If not, we've got a problem.
"If it wasn't for the points deducted to the other two teams we would be near the bottom four. Performances and results aren't good enough."
Vale's 16th defeat of the season left Glover's side 17th in League Two, 13 points from the relegation places.
Without the deduction of points for Bournemouth and Luton, they would have been just eight points away from the drop zone with 19 matches remaining.
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