Until Tuesday, the Derby County striker Martyn Waghorn had met Wayne Rooney only once, in the aftermath of his debut as a professional on Boxing Day 2007 when the then 17-year-old from South Shields was given a surprise start for Sunderland at the Stadium of Light.

It had been a remarkable day for Waghorn, ending in a 4-0 defeat for Sunderland in which Rooney had been at his very best, scoring one, creating another and a shoo-in for the sponsors’ man of the match award. Waghorn had been awarded the equivalent prize for the home team and the callow teenager found himself briefly alone alongside Rooney in a small room as they waited to get their awards and shake a few hands.

Struck by the awkwardness of it all, and a lifelong United fan from his days at their Gateshead Stadium centre of excellence, Waghorn decided to break the silence. “At that point I was just a young kid,” he recalls now. “I wanted to say something to him so I just said, ‘You’ve just got us 50 points for my fantasy football team’. I really didn’t have a clue. He laughed and said, ‘Brilliant lad, well done’.”

On Tuesday, Rooney was in Derby, whom he will join in January, one of the shock moves of the window that brings England and United’s record goalscorer back from Major League Soccer as a player-coach. Waghorn is delighted and he has already tweeted, tongue-in-cheek, that he will wrestle the greatest English player of his generation for the No 9 shirt which currently bears Waghorn’s name. He describes the excitement in the Derby squad as they first heard the news, broken by The Daily Telegraph’s James Ducker, and then the realisation after the opening night win over Huddersfield Town that it was really happening.

“It is phenomenal for us,” Waghorn says. “Him coming in January just gives us another lift in the second half of the season. To have someone like Wayne Rooney, his attitude and desire, is going to be second to none.”

Now 29, Waghorn has a spring in his step ahead of Saturday’s Pride Park opener against Swansea, established as a first choice Championship striker after a career that has seen five transfers and as many loans. The former teen prodigy who broke into the Sunderland side alongside his youth team peers Jack Colback and Jordan Henderson feels in a good place, and we have met near his home in the Derbyshire countryside to discuss something important to him.

Waghorn is the latest professional footballer who wants to say that he has suffered from depression and that he would like others, in the game and beyond, to talk openly about it. Speaking publically has been a big decision, taken with his wife Leoni, and the emotion in his voice is clear as he discusses its effect on him and his family.

It struck during his second season at Rangers, 2016-2017, while he and Leoni were living in Glasgow with their young son Ruben and was the key reason for Waghorn’s subsequent switch to Ipswich Town two years ago. His rejuvenated form there brought him to Derby last summer. Back in 2016, after his 20 goals in the second tier had helped Rangers win promotion to the Scottish Premiership, he began that second season well. Then injury and loss of form struck and he went without a goal in the league from the opening day on Aug 6, to Dec 16.

Eventually Leoni persuaded him to see the club doctor who immediately diagnosed depression. Waghorn loved playing for Rangers - the big crowds, the rich history – and he wants to make that clear. He just found the pressure that went with it hard to bear, living in a city where fans are divided so militantly. He found the injuries difficult to deal with, so too being played out of position, and then a fall-out with manager Mark Warburton all contributed to a downward spiral.

Waghorn struggled to cope with the extreme pressure of playing for Rangers credit: Reuters

“Having my family around in the city, I found what was most difficult was how intense playing for a club like that was,” he says. “Everywhere you go you get questioned, followed, photographed. In the press or on social media. That’s the side I struggled with. I am quite quiet and family-orientated. Not performing to the level I wanted in the second season was when I started to struggle.

“I got injured at the start of the new season. I think that is where it escalated. I started to struggle off the field and with the demands of playing for the club. Not being fit. Not doing as well as I could have done. The team were struggling and that was when I struggled to cope with it all. This is when I kind of got diagnosed with depression.”

He had turned down a contract offer in the summer of 2016 because he felt that with better performances he could earn an improved deal. Leoni noticed that he started coming home from training and sleeping rather than interacting with his young son. Having always been a dedicated trainer he was struggling to get up in the morning. The positive personality that had always seen him cheerfully move clubs in search of first team football was gone.

“For me [being diagnosed] was a big shock,” he says. “I have always thought of myself as an open, happy person. To hear that was a big struggle. It all made sense. How I was as a person was translating onto the pitch. I remember away at Dundee [Feb 21, 2017], just after I spoke to the doctor, I could not think about the game. My mind was completely away with it. I was receiving passes and my mind was going blank. And that was when I knew this was a genuine issue.

Waghorn has a spring in his step after the news of Wayne Rooney joining Derby credit: Getty Images

“I went and got some help and saw a few people, independent counsellors, and the Scottish FA were really helpful. It was a difficult period in my career coping with the demands of playing for Rangers. It is not something I have spoken about publicly. From where I am at now I am delighted I can say I have got through that difficult period with help from my wife, and my family.”

Talking about it with his family and professionals helped him cope with the problem. The move to Ipswich took him out of an environment that he struggled with and 16 Championship goals later he went to Derby in a deal worth up to £7.5 million. He hopes that speaking about depression will encourage others to do the same.

“I was worried who I spoke to. You don’t want it getting out. You don’t want it to damage your reputation. I was putting on a front at training. Going home I was a completely different person. People don’t see that side. They don’t understand the struggles you go through.” He is grateful to have such a strong family around him, especially Leoni and his parents, and for their love in helping him through. He is relishing the new season and the arrival of his famous new team-mate in January.

“We want to get ourselves in a good position for when Wayne arrives,” he says. “From where I started my career to now having the chance to play alongside him is a dream come true. I want to drive the team forward as a senior player. In terms of what I can offer the team, I feel like I have a real purpose.”