Harry Wilson joined Cardiff on loan for less than the £1.2m fee Liverpool were said to be demanding for the winger.
The Liverpool and Wales winger looked set to join Swansea earlier this week but then opted for Cardiff City, who have reportedly agreed a lower fee but with increases if the Bluebirds are promoted.
‘Informed sources tell WalesOnline that Cardiff have paid short of seven figures at this stage to land Wilson, but if he helps them into the Premier League they will pay potentially double, or even treble that sum to the Premier League champions.’
It is thought that Cardiff are paying a portion of Wilson’s wages, thought to be £60,000 a week.
Wilson said: “I’m looking forward to getting started here. We had a few clubs enquire about me but as soon as I heard Cardiff were interested it was a place I wanted to come.
“The Welsh connection was a massive part for me. When I come here, I feel at home. I think the team and facilities we have, everything is built for a Premier League team.
“I’m determined to come here and do my best to help the club get there.”