Yea you still got hurt on the job. If you want to get technical you got hurt before you got fired/suspended so you are entitled to comp. But that can also bite you in the ass. They might go around and say you got hurt because of an accident that got you fired so you wont be entitled. I'm a fighter tho, so what I would do is fight it for everything that it is worth. You got hurt, you are entitled to comp.
.....I've had the impression they could not fire you if you were on disability and drawing comp for an event (accident) for which they wanted to fire you. My impression is they need wait untill you have been released.
I've always thought they did this to avoid being accused of terminating someone to deny them worker's compensation benefits, which would be illegal.
Contact a lawyer who deals with work comp cases. Each state has different laws regarding the administration of comp. A lawyer would know the laws in your particular state. DO NOT trust UPS or Liberty Mutual to do the right thing. If you can't find a lawyer your local should have someone they can refer you to.