Alexander Isak wants to explore his options for a move away from Newcastle this summer after missing their pre-season tour of Asia. The club has selected a 30-man squad, but said the Sweden striker "misses out with a minor thigh injury".

It is understood some of Europe's top clubs have been aware Isak has been looking to take the next step in his career. A source has told BBC Sport Liverpool are still interested in the 25-year-old, despite signing Eintracht Frankfurt striker Hugo Ekitike for an initial £69m.

On Saturday Newcastle manager Eddie Howe said Isak would "absolutely" be part of the squad for the games in Singapore and South Korea.

BBC Sport has contacted Newcastle for comment. Isak scored 27 goals in 42 appearances in all competitions for Newcastle last season.

He was left out of Saturday's 4-0 defeat at Celtic in the first of their pre-season fixtures. Newcastle have maintained Isak is not for sale and, speaking at the weekend, Howe said he was "confident" the player will be at the club at the start of the season.

"It's difficult for me to give 100% clarity on any player," Howe said after the Celtic game. "Alex is happy at Newcastle. He loves the players he plays with, the staff, the team and I've never had any issue with him."

Newcastle had a £70m bid rejected for Ekitike, while they have an interest in Brentford forward Yoane Wissa.

Newcastle face Arsenal on Sunday in Singapore before travelling to South Korea to play a K-League All-Star team on 30 July and Tottenham on 3 August.