Rib injury

I have an athlete who has suffered a couple of broken ribs.

He literally can’t do much just yet but I was wondering if there are any suggestions for him.

Breathing is a little strained when a deeper breathe is taken. General movement of the whole body is heavily reduced. I am thinking of any seated lower body exercises. Feet, knee joint and isolated movements are about all he can do.

Any thoughts would be appreciated.

Cheers.