You can cook any frozen meat, it just takes twice as long as thawed meat. Is it recommended? Not really. I've done it more times than I care to admit, and IMO it doesn't come out as nice as a thawed piece of meat.
If you take it out now and put it in the fridge, it should be closer to being thawed by Saturday. If you have a microware with a defrost setting, you can use it. Mine says to input the weight of the meat then hit defrost. It uses a 30% power setting for defrost. I usually put in half the weight and hit defrost, then depending how much more thawing it needs, I use the 30% power setting and do a few more minutes at a time until it is thawed. That way I don't cook the meat with the microware and I truly just thaw it.