[Bottom Of The Sixth]

I started a historical major league in 1900 and had settings set at 25 man roster, 40 man secondary roster, and had one minor league team with ghost players. I had an inaugural draft (I have not had a "rookie" or 1st year player draft yet) that only added 12 players to my major league team with no one "shown" on any of the minor league teams. I had to have the AI fill rosters with fictional players. Since then, I am up to 17 players playing in the middle of pre-season games. When I look at the unsigned free agents list, there are seven players shown. However, I can not make an offer to these players to try to sign any of them. Is there any reason why I can not make an offer?

Thanks