Everton striker and England under-20s World Cup hero Dominic Calvert-Lewin has revealed how a loan spell at non-league Stalybridge Celtic helped toughen him up for the big time, with one bad challenge requiring him to go to hospital.

Calvert-Lewin, who has signed a new long-term deal at Goodison ahead of Monday night’s game against Swansea, was just 17 when Sheffield United shipped him on loan to Stalybridge in the Conference North.

‘It was a humbling experience. We trained on a leisure centre pitch they’d rented for a week and was playing alongside people who had been in the league, while others had jobs and played.

Dominic Calvert-Lewin has revealed how a loan spell in non-league helped toughen him up

‘I signed two days prior to my debut and within 20 minutes I’d been smashed in the face with an elbow. I had a big black eye and went to A&E that night. That was my first taste of it and they said to me “welcome to non-league football.”

‘I could hardly see but I played the full 90 minutes, scored two and set one up. From that moment on I knew I was going to enjoy it. I could have turned around and said ‘this ain’t for me’ but I rose to it. As soon as I got smashed in the face I wanted to smash the player that did it. That’s just the way I’ve been brought up.

‘Briggsy (Keith Briggs, manager at Stalybridge) still messages me now to say well done if I’ve scored goals or put in good performances. For me, Stalybridge doesn’t seem that long ago but it came at a crucial time in my development.

Everton and England under-20 starlet Calvert-Lewin played for Stalybridge Celtic

‘It was my first bash at men’s football, competitive football. It was massive in toughening me up and enabling me to produce what I’m capable of now.’

Things have moved on rapidly for Calvert-Lewin since then. First, there was the £1.5million move from Bramall Lane to Premier League Everton in 2016. And last summer he became the first Englishman since Geoff Hurst to score in a World Cup Final when his goal beat Venezuela 1-0 in the under-20s final.

Despite Everton having three different managers this season, he’s equipped himself well with six goals, a record bettered only by Wayne Rooney. ‘I’ve made massive strides in 18 months or so,’ he acknowledges. ‘It’s gone really quick but to look how far I’ve come, it’s crazy really but I’m thoroughly enjoying it.’

The highly-rated 20-year-old has just signed a new long-term deal at Goodison Park

The spotlight of the Premier League can be intense as Calvert-Lewin found out last weekend when he won a penalty in the Merseyside derby to earn his side a draw.

Jurgen Klopp believed the youngster had gone over too easily from Dejan Lovren’s push but most observers thought the contact was sufficient to warrant a spot-kick.

‘That’s football. I’m playing at the top level now so I’m bound to be put under the microscope,’ he says. ‘I don’t really react to what’s going on outside the game. Whether it’s soft or not, it’s a penalty. I’ve felt contact in the box and that’s that.

He was just 17 when Sheffield United loaned him to Stalybridge in the Conference North

‘In terms of the reaction I can’t do much about that. It happens a lot in the Premier League where referees make decisions and one team agrees, one team doesn’t. That’s just the nature of the game.’

Everton are unbeaten since Sam Allardyce replaced interim boss David Unsworth, who himself stepped in after the sacking of Ronald Koeman. ‘There is optimism, 100 per cent,’ says the 20-year-old. ‘Particularly off the back of recent results.

‘It’s a lot about momentum in football and confidence. A couple of months ago we were low on confidence and we suffered because of that. You get one win, then back-to-back wins and it’s massive. You’ve seen that in the last few weeks. We then take the confidence from that into upcoming games.’

Calvert-Lewin is set to face Swansea City with an improved Everton side under Sam Allardyce

Allardyce has brought an attention to detail that Calvert-Lewin believes has helped. ‘The confidence comes from preparation, the defensive work we’ve done to become a complete unit; defenders, midfielders, attackers.

‘You take confidence from that. You have a gameplan and know what to do on the pitch. If you believe in that strategy then you reap the rewards. I knew that whatever manager came in, it would be a clean slate for everyone.

Allardyce is understood to want a proven striker in January with Everton not properly replacing Romelu Lukaku last summer despite spending heavily on other areas of the pitch.

Dominic Calvert-Lewin (R), Jonjoe Kenny Mason Holgate (L) and boss Sam Allardyce

Calvert-Lewin has played up front and out wide this season - he’s good in the air besides his natural speed - and isn’t afraid of more competition. ‘There is only one answer to and that is to rise to the challenge,’ he said.

‘It’s the Premier League, the most competitive league in the world. No matter what team you play for in this league, there is always going to be competition and people brought in, so I would welcome the next man in.’

The Swansea game gives a chance for Ashley Williams and Gylfi Sigurdsson to face their former club.