"We never feel 100 percent," Casilla said with a smile.
Manager Bruce Bochy said it's unlikely the shutdown reliever, who has boasted a 1.89 ERA in 21 appearances (19 innings), will be activated on the Giants' current road trip.
But Bochy was pleased with the progress he saw from Casilla today and will soon make a decision on the next step of the rehab process. Casilla last pitched May 20 and had not allowed a run in his last six appearances.
"Felt good, we'll see how he comes out of it," Bochy said. "We'll make a decision tomorrow morning for him on what the next move is. But possibly could be starting rehab real soon."