West Ham assistant coach Mark Warburton admitted frustration after their Carabao Cup elimination.

Despite having 22 shots to Blackburn's six – 17 of which came from inside the penalty area – the visitors emerged with the spoils after drawing 2-2 after 90 minutes and triumphing 10-9 from the spot.

Warburton later said: "It's that little bit of quality to get that end product from a good period of football [that's missing].

"Let's be honest; we started the game poorly tonight and let ourselves down in the first five or six minutes with the manner in which we started the game.

"But then we started controlling the football more and went in as we did – and then the second half was much better.

"We were dominant on the football, passed forward, got into great areas and created chances. But football is about scoring goals – goals change games – and we just didn't get the final touch to get the rewards in the second half.

"To concede in that manner, late in the game, was very frustrating.

"On Sunday, we had a good attacking position in the 92nd minute, which we don't capitalise on, and 30 seconds later the ball's in the back of our net and we have to recognise that.

"Of course it was mentioned, of course it was looked at and studied, but again tonight from a good attacking area, we let ourselves down, don't defend our goal properly, allow a dangerous player back onto his stronger side and we paid the price for it.

"As a team we did enough to move into the next round, so we're disappointed that we haven't. It's the final bit of quality in the final third, we lacked it, we went to the lottery of penalties and paid the price.

"The margins are so fine at this level, at Premier League level especially.

"That chance that just goes wide at the far post, or in at the post, that's what we're talking about here.

"I think we've seen lots of good periods of football. You look at the second half against Liverpool for example, you look at Man United, I thought that was a superb away display and we came away with nothing.

"That's more than frustrating. The players worked so hard, showed their quality and deserved something from both games.

"We look at the season thus far and say we've dropped points that in truth we should really have gained to put us in a stronger position. We're disappointed tonight, of course, and now we go into the weekend, which we know is an important game, and there's more than enough quality in the squad to show what we're capable of."