Eoin Morgan has suggested that England’s underperformance at the World Cup in India is unparalleled across sport and that their players are “definitely unsettled” after heavy defeats in four out of their five group games.

England have not been mathematically eliminated from the tournament – even defeat in Lucknow on Sunday will not officially knock them out – but they are unlikely to qualify for the semi-finals even if they put together an improbable run of form and win all four of their remaining fixtures.

Morgan, who captained them to the 2019 title, said it had been “unsettling” to watch England’s plight over the last three weeks and that their confidence had taken a beating. He also hinted at wider issues than simply form, saying: “I think there’s something else going on – there has to be.”

And Morgan went as far as to suggest that England’s campaign has been among the worst in sporting history, in the context of the widespread expectation that they would reach the semi-finals. “I’ve never come across a sports team that has underperformed like this England team, given the level of expectation that is on their shoulders,” he said on Sky Sports.

“There’s something within the team that is definitely unsettled. The method which they’re trying to use and given the substantial nature in which they’ve lost the game[s], it is definitely called into question, the morale within the changing room and the confidence. It must be at its lowest that it’s been for a considerable period of time now.”

Morgan said that it was “an unacceptable excuse” to simply say that players were all out of form at the same time. “I think there’s something else going on – there has to be,” he said. “When you look at the strength in depth, particularly with the bat, England are as good on paper as any other side in this tournament, but they haven’t yet fired.

“They’ve made mistakes with selection: they’ve really struggled to find a balanced side and one that’s effective enough to compete, never mind win this tournament. It’s been unbelievably challenging for Jos and his team… they have to regain the confidence in the method that they’ve used for so long that has made them double world champions.”

Marcus Trescothick, England’s assistant coach, said that the squad are “feeling the heat” and “gutted” about their results to date, and admitted that he has been unable to get his head around their collective failures with the bat. England have lost 47 out of a possible 49 wickets (Reece Topley was absent hurt against South Africa) and no batter has made an individual 50 in their last two matches.

“The thing that’s baffled me the most is that it’s been consistent across the board,” Trescothick said. “Bar the game at Dharamsala, where we played Bangladesh, where one got a big score [Dawid Malan’s 140] and we got a few other big scores around it, there’s just never been the consistency of people getting the runs.

“I think they’re trying to understand it… it [their form] has not gone, it’s just hiding in a funny place at the moment. It’s not suddenly disappeared and they’re never going to score runs again. They’ll rebound from this and rebound back into form at some point. But it might be, unfortunately, disappointing that it’s going to be too late for this competition.”

Sunday’s match in Lucknow will be played on a used pitch, the same one that was used for South Africa’s win over Australia two weeks ago.

“The timing actually couldn’t be any worse,” Morgan said. “Given India are still out and out favourites to win this tournament on home soil, that challenge just becomes far bigger now than it probably would be if you were playing on a fresh pitch.

“England just have to play what’s in front of them,” he added. “For a lot of this tournament, I believe that they’ve been carrying other things or looking outside of the camp, as opposed to their own performance. They need to stay in the present for as long as they can tomorrow and turn India over.”