It is an indication of the fire and enthusiasm coursing through Slaven Bilic that one answer – the first answer to a gentle opening question of simply “how are you?” – to start this interview takes precisely 10 minutes and 40 seconds to complete.

In short, the West Ham United manager is happy. Very, very happy ahead of the Premier League season opener at Manchester United on Sunday.

A hip replacement, his second, has increased his mobility, “100 per cent, totally” changing his life, while West Ham have undergone major surgery in the transfer market after a difficult campaign.

“It was not an enjoyable season and it was the season when we suffered but you only improve through suffering,” Bilic says. “When do you improve your fitness? When you suffer. If you are jogging and it’s easy you are not going to get fit. You have to suffer. So was it enjoyable? No. Would I like it to happen again? Of course not. But would I swap it for the season before after it finished? No. No. Because it builds you. It makes you stronger.”

It is a telling response. West Ham are stronger. In has come Marko Arnautovic, for a club record fee of up to £24 million, Javier Hernandez, Pablo Zabaleta and, on a season-long loan, Joe Hart. All four were Bilic’s first-choice signings – and it is rare for a club to be able to pull that off.