Chris Brunt was disappointed after Serbia came from behind to beat Northern Ireland in Euro 2012 qualifying Group C.
Brunt helped put Nigel Worthington's side ahead five minutes before the interval when swinging in a dangerous free-kick from the right which Gareth McAuley headed home.
But Serbia were level on 65 minutes when Marko Pantelic slotted home, before Zoran Tosic then won it with 16 minutes remaining.
Brunt told Sky Sports HD1: "First half we played pretty well and second half, same old story, got a goal up and couldn't hang on to it.
"Well, we shot ourselves in the foot, we dropped too deep and invited Serbia on to us and they've got good players and they're going to put pressure on you and that showed second half, we just couldn't get out (of their own half).
"I think we've let ourselves down and it's disappointing."
He added that work-rate was not a problem with Worthington's side, rather a failure to be clinical.
"Work-rate's never an issue in the qualifying games and we showed that again tonight," he said.
"But ultimately we just weren't good enough when we got the ball."