Rasmus (core muscle surgery) has resumed facing hitters after he was briefly shut down due to back stiffness, MLB.com's Alden Gonzalez reports. Rasmus is just about at the tail end of his recovery process from the surgery he underwent in March to address a core-muscle issue, and it appears he was also able to quickly shake off the back ailment to stay on track in his recovery. The 26-year-old had been set to begin a rehab assignment last week before the episode of back stiffness set in, but with that minor delay behind him, he should be ready to join a minor-league affiliate in the near future.