The Borussia Dortmund right-back, 28, lines up alongside Manchester City striker Erling Haaland in the Norway squad and arrives at the tournament off the back of a career-best campaign in the Bundesliga, where his tally of 15 assists eclipsed anything he had previously managed in a single season.
His display in Norway's last-16 win over Brazil caught the eye in England, with the full-back nullifying Vinicius Junior for 62 minutes despite having barely trained beforehand because of a calf strain.
"It was the calves," Norway boss Stale Solbakken explained of the decision to withdraw him. "Fortunately, the injury held, it's just the strain; he hasn't trained enough. He'll look even better in the next game."
Dortmund would prefer to keep hold of Ryerson and hope to open contract talks once his World Cup involvement ends, with less than two years left on his current deal. According to BILD, the German club would consider offers above £26m for a player who cost them just £4m two and a half years ago, with other unnamed clubs also said to be tracking his situation.
Manchester United are also credited with an interest in Ryerson's Dortmund team-mate Felix Nmecha, who impressed for Germany before their round-of-32 exit and is reportedly rated as United's top target in midfield. Newcastle, who have already sold Sandro Tonali to Tottenham, are said to view the former Manchester City academy graduate as their leading option too. Dortmund's valuation of Nmecha, at around £103m, dwarfs the fee being discussed for his full-back team-mate.
United's interest comes as Michael Carrick's side reshape the squad following Casemiro's departure and Manuel Ugarte's long-term injury, with a right-back also wanted given Noussair Mazraoui's fitness issues over the past year.
Diogo Dalot remains first choice there, but United want a productive alternative in the final third. Ryerson's pace, physicality and end product are understood to fit the profile being targeted, even with other suitors also monitoring developments in Germany.