Hello, my friend!
I'm terribly sorry to say that we won't be able to meet tonight.
I got injured during our sports competition. It was a complete accident.
During the game I wobbled and twisted my ankle. It hurt a lot.
I had to be sent to hospital. I don't think we will be able to meet any time soon.
I'll probably be back in a week or two, then we could catch up!
Until later, xyz.
