After penning a new two-year deal at the Emirates Stadium, Wenger is under pressure to strengthen ahead of the new Premier League campaign and he has claimed that he only intends to sign a maximum of three players.
Left-back Sead Kolasinac has already arrived from Schalke 04, but Nicholas wants the Gunners boss to go all out to try to sign players of the calibre of Raphael Varane and Alexandre Lacazette ahead of their rivals.
The Scot told Sky Sports News: "Wenger needs to unload six or seven of the weaker players, and, rather than signing more squad players, he must bring in another world-class defender, a top midfielder and a 20-plus goal striker.
"He needs another top midfield player with Santi Cazorla out. Raphael Varane or Virgil van Dijk would be ideal at centre-back and Alexandre Lacazette is the striker I wanted and hopefully the Atletico Madrid transfer ban means we've got a chance."
Both Varane and Lacazette - of Real Madrid and Lyon respectively - have been linked with moves to the Premier League with Manchester United and Liverpool.