Well, in my 35T team I had a string of bad results that just killed my morale. I have 0$ bonus set on that team, I need every cent I can get.

I figured it would be a good experiment in how they behave with the starting eleven all in yellow morale, one orange.

I have tried to be there for matches to see how they do, and to get the boosters to fix them up.
Well, they did get a couple more cards the next few games, but I lucked out in that I was facing some lower teams, so I had some good wins, the guys got good ratings and some improved out of the yellow!

The other thing I notice is if you fix them up to 100, they seem to take longer to lose morale, so maybe there is a minor relation to morale/cards/ratings.