Watford boss Sean Dyche blamed missed chances for his side's shock Carling Cup first round exit at the hands of League Two Bristol Rovers.
The Championship side took a third-minute lead through Marvin Sordell's close-range shot, but Matt Harrold fired a 25-yard equaliser two minutes later and Rovers went on to win on spot-kicks.
Dyche said: "It is the story of our season so far. I don't know how many chances we missed but I will find out when I look at the stats.
"We did everything but win the game. But you have to be clinical in front of goal and that is missing from our game at the moment.
"Obviously the Championship is our priority, but having enjoyed cup success myself as a player, I know what a boost it can give a club and I'm disappointed to go out of the Carling Cup so early.
"So many aspects of our play are pleasing me, but unless we start putting away our scoring opportunities that will count for nothing."
Delighted Rovers boss Paul Buckle admitted that Mustapha Carayol had disobeyed instructions when netting the winning penalty in the shoot-out.
"I told him on no account to check his run up before shooting, but he did exactly that and scored so what do I know?" he said.
"I thought we deserved to win. It was a fantastic effort from all our players, especially as we lost Cian Bolger, Matt Harrold and Chris Zebroski through injury.
"They are three big players for us. Bolger's injury is the worst of the three, but we'll have to wait to see whether any of them will be fit for Saturday.
"We now go to Leyton Orient in the second round and will approach that game with plenty of confidence. This is starting to look like my team and I saw a lot to please me tonight."
Goalkeeper Scott Bevan was Rovers' hero, saving two shoot-out penalties from John Eustace and Carl Dickinson.
Apart from Carayol, Jo Kuffor, Adam Virgo and Wayne Brown netted penalties for Rovers, while Sordell and Adrian Mariappa were Watford's shoot-out scorers.