FIFA 12 - Match Forfeiting in Career Mode

[adamclark83]

For the past few nights, I've been playing Career Mode using my own created player. I'm currently playing the second season and what I'm finding infuriating is that at some times when I select "Next Match" a box pops up saying something like this:

You do not have enough match-fit players for your next match. You will immediately forfeit the match and the score will be 0-3. Do you wish to continue?

I take a look at my players and for everyone it says they are all fit and healthy and no one has been injured. What's with this? Sometimes I have to load an earlier save to avoid it. Is there any way around this?