The Jazz and the doctors already know if it's an ACL or not. A Lachman test is easy to do and will show pretty darn conclusively if the ACL is severed or not. MRI is really only necessary if the test is inconclusive (minimal shift between tibia/femur). It's extremely painful to do it right now, but once it swells up to a grapefruit, all mobility to move the knee is lost.
Having torn my ACL in much the same way, it's time to start praying that Burke turns it on this year.
And I know we'd like to make the best of him being on the sideline, but I hobbled over to the sideline, put some ice on it and sat and watched the rest of my soccer game in the same manner. I will admit that it's a bit strange that he wouldn't be icing it and would have it simply wrapped.