Alexander Isak has reportedly told Newcastle he wants to explore a move away as the club confirmed he was not part of the squad travelling to Asia for pre-season friendlies.
The Daily Mail said on Thursday that Newcastle bosses "are aware of Isak's wish to consider his options this summer".
It came hours after the Saudi-owned Premier League club said the 25-year-old forward would miss the Asia tour "with a minor thigh injury".
Isak's 23 Premier League goals last season made him one of the world's hottest properties and he has been linked with English champions Liverpool.
The Mail said Liverpool were still interested in acquiring the Sweden international despite announcing the signing of Eintracht Frankfurt striker Hugo Ekitike on Wednesday.
Ekitike's arrival, for a reported initial fee of £69 million, takes Liverpool's spending during the current transfer window to more than £250 million.
Isak still has three years left on his contract at Newcastle, whom he joined in 2022 from Spanish side Real Sociedad.
He was left out of Saturday's 4-0 defeat in a friendly at Celtic.
But Newcastle boss Eddie Howe said at the time he was "confident" that Isak would stay at St James' Park, adding that he expected him to be part of the Asia tour.
"It's difficult for me to give 100 per cent clarity on any player," he said. "I'd never sit here and do that because it's football and you never know what could happen.
"All I can say is that Alex is happy at Newcastle. He loves the players that he plays with, the staff, the team."
Newcastle face Arsenal in Singapore on Sunday before flying to South Korea, where they will play a K League all-star team and Tottenham.