Like Vinny said, I would thaw it, sprinkle a little more rub on it and cook it as normal.
(Brewmaster and Pitmaster)
BBQ Team: Lawn Guyland Smokers
Brewery: Black Dog Brewery
"Sam I Am": XL Big Green Egg
"R2 and D2": Twin 22" Weber Smokey Mountains
Custom Made Automated Souped Up Sabco