The Scot has already brought four new players to the Stadium of Light.
The Scot took charge of the Black Cats last month after Sam Allardyce departed to take charge of England.
He has had to move quickly to secure new signings ahead of the season, with Papy Djilobodji, Donald Love, Paddy McNair and Adnan Januzaj arriving already.
Sunderland manager David Moyes
More signings will be needed if they are to avoid another relegation battle this season, with the current squad lacking in several areas.
And Nicholas says he believes that Moyes can be more aggressive to the board in his demands for signings.
“I think David Moyes can afford to be a bit more aggressive towards the owners," he told Sky Sports.
“I don’t mean with a physical threat, I mean going after players aggressively and saying I need this position sorted. I think it’s going to take him five or six weeks.”
David Moyes with Adnan Januzaj
It now remains to be seen if Moyes can secure the players he thinks Sunderland need to secure to ensure they are comfortable this season.
Another striker will surely be top of his wishlist, with the club still relying heavily on Jermain Defoe heading into the new season.
Whether he can get one though is another matter entirely, with the Black Cats not the only side in the hunt for a forward this summer.
Sunderland manager David Moyes before the match