Newcastle are exploring a move for RB Leipzig striker Benjamin Sesko in case Alexander Isak departs this summer
Isak has not travelled with the Magpies for their pre-season tour of Asia as he considers his future at the club amid interest from Liverpool.
Sesko was heavily linked with Arsenal until the Gunners shifted their focus to Sporting striker Viktor Gyokeres.
Liverpool, Manchester United and Chelsea were also keeping tabs on the Slovenia international earlier in the window.
Newcastle will only attempt to sign the 22-year-old, who scored 13 goals in 33 Bundesliga appearances last season, if Isak leaves.
Newcastle said Isak, 25, didn't travel to Singapore with the rest of the squad due to a "minor thigh injury".
Isak scored 27 goals in 42 appearances across all competitions for Newcastle last season and his exit would leave the north east of England club outfit lacking options in the final third.