Holt has been in constant contact with concussion specialist Dr. Michael Collins and will travel to Pittsburgh to visit with him Wednesday, the Boston Globe reports.
The Red Sox were hoping Holt could begin a rehab assignment pending the doctor's evaluation, but he continues to feel the lingering effects of a concussion that put him on the disabled list a little more than two weeks ago. One of the bigger challenges for Holt is tracking fly balls, a time when his head may have to move quickly while on the run.
