Sprained ankle- what exercises can i do without putting weight on it?

So i'm a high school rower, and during a run yesterday i took a bad step and kind of twisted my ankle. it's nothing serious but it looks like i won't be able to put much weight on it for a few days. anyway, i still have practice, and my coach wants me to do exercises that don't involve me standing on it. i'm thinking circuit-type stuff, strength exercises...sit-ups, push-ups, etc. does anyone have any other ideas for exercises i can do without standing on my foot? thanks.