The club has already signed three players – Sven Botman, Nick Pope and Matt Targett – so far in the transfer window, and attention is now focused on the attacking recruits Eddie Howe feels that he needs for the coming season.
Newcastle have an interest in 22-year-old Bayer Leverkusen winger Moussa Diaby, though his club may price him out of a move to St James’s Park.
Simon Rolfe’s, Leverkusen’s director of football, said: "I'm optimistic about Moussa that he’ll play here next season. But when clubs with incredibly large financial opportunities bid for such a player, we have to sell a top player at some point."
Hamann believes that Diaby would be a perfect signing for the club given his pace and finishing.
Speaking to Genting Casino, the former United midfielder said: “Defensively, Newcastle have been solid with their recruitment. Moussa Diaby would've been a great signing for them because he's got plenty of pace, he can create a chance out of nothing – and he's a very good finisher.
“Newcastle need to sign a winger with pace, and they need someone who puts goals away, because they haven't got an out-and-out striker who scores goals – and that's the position they need to look at strengthening.”
Hamann also gave his view on the departure of 27-year-old midfielder Isaac Hayden, who has joined relegated Norwich City on a season-long loan.
“I'm surprised Isaac Hayden has dropped to the Championship with Norwich City, but, at the same time, Newcastle probably advised him to do so,” said Hamann.
“I think Norwich will have the aim to get promoted again next season, so I think the move down to the Championship can really galvanise Hayden's career.”
Hayden missed out on a Premier League squad number for the second half of the season after undergoing knee surgery.
Reflecting on his time at Newcastle, Hayden tweeted: “Don’t know where to start. What a club, set of fans, lads and staff.
"Amazing memories, but time to move forward with a fresh challenge. All the best for the upcoming season, I’m sure it will be a great one for the club.”