Manzambi is the most prominent target. The 20-year-old Swiss international made 47 appearances for SC Freiburg last season, recording 16 goal involvements across all competitions, and was voted Europa League Young Player of the Year. Freiburg value him highly and his price tag is expected to be around £40m.
Newcastle United had previously bid for Victor Munoz at Osasuna only to see Liverpool hijack their move, which has left the club needing to identify alternative options on the wing.
Toure is also on their radar. The 20-year-old Ivory Coast winger at TSG Hoffenheim has caught the eye for his explosive pace and ability in one-on-one situations. He can operate on either flank and also as a central striker, giving him versatility that has attracted interest from Brentford as well as several other clubs this summer.
Alajbegovic represents a different type of target. Bayer Leverkusen took up their option to buy the 18-year-old Bosnia international earlier this summer but are weighing up a quick sale given the level of interest building from clubs in Italy and the Premier League. Alajbegovic has already made his mark at the World Cup, scoring an excellent goal against Qatar in his country's 3-1 victory.
Whether Newcastle move for one or more of the three remains to be seen, but the club's need for wide reinforcements is clear following Gordon's exit.
The breadth of Newcastle's search reflects both the urgency of their need and the difficulty of replacing a player of Gordon's quality and contribution. Each of the three targets offers a different profile, and the club may ultimately pursue more than one depending on how the transfer market moves over the coming weeks.