Berylson believes that manager Ian Holloway will add one or two more new faces.
"There are still some spots in the team we have to fill - at least one - but it's not like last year when [Steve] Lomas went after lots of players," he told News at Den.
"I agree that we did have to make a lot of additions then but I don't think that's true this summer. A lot of our players are looking strong.
"We could use a few more bodies but I also think that one of our kids is going to come through."
Millwall begin the new season against Leeds United on August 9.