The Villains boss criticised his team's defending, particularly from set-pieces, as they crashed to a humiliating defeat at Valley Parade on Tuesday evening
Three goals from set-pieces sent the Villains to an embarrassing defeat away to their League Two opponents, with striker Naki Wells giving the Bantams a first half lead which was subsequently built upon by two second half goals from defenders Roy McArdle and Carl McHugh.
Despite Andreas Wiemann replying for the visitors, Paul Lambert was left hugely dissatisfied by his team’s performance and they now need to overhaul a two-goal deficit at Villa Park in order to stand a chance of progressing to the final.
"I'm really disappointed we lost the game, we are in a game now, that's for sure," Lambert told Sky Sports.
"We knew what was coming - set-pieces - and we never defended them well at all. That's definitely what's hurt us but that's certainly not good enough.
"We had a lot of the game and yes they were set-pieces but set-pieces are a vital part of the game and you've got to defend them. We didn't do that.
"But it's half-time and we've got time to retrieve this. We'll see what happens in a fortnight's time.
"We know what we've got to do and we've certainly got to do a lot better than that."
The Premier League strugglers will now have to wait until January 22nd for the return leg at home against Phil Parkinson's side.