A frustrated Jurgen Klopp believes Liverpool were denied a clear penalty during the closing stages of their 1-0 English Football League (EFL) Cup semi-final second-leg defeat to Southampton at Anfield on Wednesday (25 January) night.

The hosts trailed by a single goal on aggregate when, with six minutes of the 90 remaining, substitute and eventual match-winner Shane Long was alleged to have blocked an overhead kick from Roberto Firmino with his arm.

"The ref [Martin Atkinson] again didn't see the handball of Long and it doesn't help in a game like this," Klopp lamented during an animated post-match interview with Sky Sports.

He later added: "The ref, maybe sometimes it would be really nice if when we are part of obvious things like handball we could hear a whistle. It would be nice. I don't know how often it's happened already this season. We always say nothing about it.

"After Man United it was a clear offside goal and nobody says anything, today a clear handball and nobody says anything. You ask me what did we do wrong? We didn't score. That's it. Sorry."

Klopp was generally content with his side's performance. Liverpool dominated possession to the tune of 73%, but could not find a way past a disciplined Southampton team – lacking influential defender Virgin van Dijk – that could have put the tie out of reach before half-time as Dusan Tadic and returning captain Steven Davis both spurned chances laid on by the impressive Nathan Redmond.

The eight-time League Cup winners piled on the pressure after the interval, yet failed to convert any of their opportunities, with Daniel Sturridge proving particularly wasteful. Philippe Coutinho also whistled an effort agonisingly wide of the post and, most significantly, Saints goalkeeper Fraser Forster somehow clawed the ball off the line to spare his own blushes following a failure to hold Emre Can's swerving shot.

"We did really well, you cannot create more chances than we did in the second half," Klopp said. "It's really difficult because they are a counter-attacking threat so you need to take risks, but too much risk leads nearly all the time to a counter-attack. We had big, big chances and no luck. It was a good save and then lucky from Forster."

When asked what Liverpool did not do well in their second consecutive home defeat, the manager replied: "You sat, I think, two yards behind me. You saw the game. We didn't score, that's it. What can we say? We could have scored in the second half four or five times. What question are we asking?"

An unhappy Klopp, pressed on if his team needs a change of luck to turn around a poor recent run that has seen them win just one of their seven games across all competitions in 2017, finished an awkward exchange by asking: "Do we have to fill time or what?

"I've said already the same, maybe it's because of my language. We have to score when we create chances. That's the thing. First of all you have to create chances, which we did, and then you have to score, which we didn't, and so we lost."