Are you serious?I thought it was a known fact that NT games are Arcade, similar to PL.You cannot put injured people on the field and people cannot get injured due to that game.
Having your player on a national team will not affect his player ratings or weekly minutes in any way. However, he will be susceptible to injury, and you will not be able to fire him.
If the GM' speak on behalf of the BB's, and i assume they do, yes.