Campbell once had the toughest job in football trying to break into a Manchester United forward line containing Cristiano Ronaldo, Wayne Rooney and Carlos Tevez.
And the childhood United fan wants to return to Old Trafford with the Bluebirds in the Premier League next season.
Campbell spent loan spells with Belgian club Royal Antwerp and Tottenham Hotspur before helping Hull into the Premier League with 15 goals in 32 appearances while on loan there in the 2007-08 season.
The 25-year-old eventually joined Sunderland for £3.5m in July 2009 but his impact was limited by a serious knee injury.
However, he still won his solitary England cap while at the Stadium of Light, during a 3-2 Wembley defeat to the Netherlands in February 2012.
Fraizer Campbell: “It was difficult to leave Manchester United – I was there since the age of 10 and had seen all the great players in training – but I wanted to play football.
“It was amazing to be around all great players and you had to be worth £25 million to play in that United team.
“I didn’t play many games but I had a great time and loved being part of it.
“Even when I was injured up at Sunderland Sir Alex invited me down to United to stop me getting bored of the same routine.
“So I was able to break it up a bit and that was really nice.
"They were all top players and you dream of training and playing with people like that, although even the likes of Wayne Rooney are all normal lads.
“Being injured for such a long period put me back a couple of years.
“But now I am as sharp as ever, as fit as ever, and want to push on in the next couple of months.
“It’s the best I’ve felt in a long time, when you first come back you get aches and pains in your calf because it’s not been used to running about.
“But it’s been brilliant for the last few months and I’m ready to play and score goals.
“There were times when it crossed my mind whether I would play again, you do get down days.
“But I’m really close to my family and they helped me get through it.
"It would be great to have a good run in the team, score goals and end up with promotion.
“After missing so much football I just want to be back playing and scoring goals again.
“Everyone at Cardiff has made me very welcome and you can tell there’s a good buzz around the training ground.
"The aim here this season is to get promotion and everyone feels we can do.”