A "man roster" refers to a list or group of individuals, typically men, who have been chosen or selected for a particular team or organization. Full definition
Leaving a strong impression in the spring is a great way to sneak onto the 40 - man roster when there's a need in the middle of the season. (sbnation.com)
He's part of their 15 - man roster on a guaranteed contract, so he is required to be with the team when he's not on another assignment or medical leave. (sbnation.com)
But I don't know we need to pencil him in on our 53 man roster quite yet. (sbnation.com)