His signing was one of many that would leave Sunderland fans shaking their head in the summer of 2013.
There was some excitement at the pace David Moberg Karlsson was said to possess, but it always seemed an odd move for a player who had not really shown enough promise to earn a move to Sunderland.
It is clear that my career was not ready to take such a large step so early.
As Moberg Karlsson has now revealed in a candid interview with the Swedish media, it would turn out to be a difficult time.
The then teenager - he is now 22 - lasted just a year before leaving the club, never making an appearance.
Inbetween was a doomed loan spell at Kilmarnock, where he could make little impact.
Here you can cath up with the most interesting lines from his interview ...
Why he came
“I got a chance that I could not refuse.
“It is clear that my career was not ready to take such a large step so early, but it’s very hard to say no when the opportunity shows up.
“It was too big a step for me, it was hard to move there aged 19, and especially when it was a turbulent time in the club and they changed managers.
“There were new people who wanted their players and then you have to remove others to afford them.”
Why Sunderland bought him
“I had it explained to me that they saw a great talent they hoped to refine.
“It was not that they bought me as a professional player. I knew that the sporting director (Roberto De Fanti) had an eye on me in the past and saw me as a great talent with my speed.”
“It was turbulent in the club and those who recruited me were not there very long.
“Those who came in did not care. I had it explained to me quite clearly.
“We had meetings and it was known that I was not good enough and they wanted their players. It was not just me who got to experience it, but it was difficult to take as a 19-year-old.
“It was hard, very hard, I tackled it not at all well.”
A loan spell at Kilmarnock
“There was a lot that I just wanted to get away from at Sunderland.
“I left on the last day of the window and did not really want to go (there).
“I played two matches and after we lost to Celtic I didn’t play any more.
“It’s hard to do something great against Celtic. Then they said that they could just as easily play with their own young players – they paid nothing for me then Sunderland paid full salary.”
On not taking Seb Larsson’s advice
“He told me exactly how I should behave to succeed but I did the opposite and went my own way.
“Had I only listened to Sebastian Larsson, so everything had gone better.
“Why I did not do it? It is hard to say. He has had a long career in England.”
Moberg Karlsson’s Sunderland career
Signed: June 2013
Fee: £1.65 million
Loan Appearances at Kilmarnock: 4
Left: August 2014
Played for since then: FC Nordsjaelland, IFK Norrkoping