Maximum players on a team

Hello,

I believe we can't have more than 30 players in our team. That's why I can't make any bid now because I already have 30 players in my team.

But I have just seen a team with 31 players. I think this is when you have 30 players and you buy a 17 years old player. He is considered as a youth, but he arrives into your first team.

Perhaps nicmo could fix it ?