David Moyes said his West Ham side were 'lacking' in front of goal after their 1-0 defeat to Sevilla in the UEFA Europa League Round of 16 first-leg.
The Hammers were wasteful in front of goal for the second game running and like the Premier League defeat to Liverpool, left empty handed.
Nikola Vlasic spurned a glorious chance in the opening 45 minutes.
And West Ham were punished when Munir El Haddadi's found the back of the net after break, his second-half strike proving to be the difference on the night.
Speaking after the match, Moyes reflected on the chances missed in Spain.
"We had opportunities tonight, we did a lot of good things but Sevilla are a tough team a very very good team. We did enough for a draw, we had chances but also Sevilla had some opportunities.
The Vlasic chance was huge and Lanzini's too. It is a regular occurrence in the last few games, we should have probably got a point at Anfield and tonight we could have easily got a draw as well so we have to turn the good chances into goals, because at the moment we are not finishing off after good work and effort and we need to take those chances.
There were opportunities where we could have set other things up better, we could have made better chances so that is something I need to push again this week.
"But they know that, we had a period earlier in the season where we had a similar run of not scoring and that is when you have to keep clean sheets. For long period we defended well and it was just a lapse of concentration and the last two games we narrowly lost.
West Ham can turn the tie around when Sevilla visit the London Stadium on March 17.
