The Blues take a one-goal deficit back to Stamford Bridge in two weeks’ time (Picture: Getty)

Mauricio Pochettino says Chelsea were ‘the better side’ in their 1-0 Carabao Cup semi-final first-leg defeat to Middlesbrough and were let down by their profligacy in front of goal.

The west Londoners enjoyed 72 per cent possession in Tuesday’s match and had 18 attempts on goal compared to Boro’s six, but were undone by a slick move shortly before half-time that saw hometown lad Hayden Hackney fire the hosts ahead.

Cole Palmer missed a hat-trick of gilt-edged chances in the first half, though Chelsea created far less in the second period as Middlesbrough dug in and defended brilliantly.

A lack of clinicalness in front of goal has been a feature of Chelsea’s season and Pochettino was disappointed that his side were unable to convert their control into goals, but he was largely content with the performance and confident of turning the tie around at Stamford Bridge in two weeks’ time.

‘I think today the approach was good, we cannot say anything about the attitude,’ the Argentine told Sky Sports afterwards.

‘Only that we made some mistakes in the first half, I think we gave the chances to score and then, yes, they were so aggressive and really tough.

‘They played in transition, in counter-attack, and with a really deep block. It was difficult for us to break down this block.

Hayden Hackney scored the only goal of the semi-final first leg (Picture: Getty)

‘We had many chances to score and didn’t score, that is football, of course. Really disappointed, but it is the first half of the tie because after this 90 minutes we have another 90 minutes at Stamford Bridge. I think we need to be positive.’

Asked what he puts Chelsea’s profligacy this season down to, Pochettino continued: ‘I think it’s how we compete. We made some mistakes and we were punished for that. In football that happens.

‘There’s only to be tough and to keep pushing. But disappointed because I think if we assess the performance we were the better side, we created more chances, we create clear chances.

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‘But we didn’t score and we were not clinical – and that has happened during this season, after six months I think it has happened a lot. So many games that we didn’t win because we were not clinical enough.

‘We have a lack sometimes of [killer instinct] to score. It’s not that we’re not creating chances, we are creating too many chances, but we are not scoring them and in this type of game if you are not scoring it’s difficult to win.’

Chelsea’s travelling supporters booed the players at full-time, which prompted Thiago Silva to go over to the away end to try and calm them down, and Pochettino feels they were within their rights to be disappointed.

Asked about the incident at full-time, he added: ‘I did not see, I did not see what was going on there. I cannot say nothing about that, only that of course we understand that our fans should feel disappointed about that but there’s still 90 minutes to play.’

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The Blues must overturn a one-goal deficit at Stamford Bridge in two weeks’ time.