Sandoval (biceps) walked one over 1.1 innings for Triple-A Worcester on Friday.
Sandoval had been scheduled to throw one inning, but he went back out after cruising through his first inning, per Triple-A Worcester's official site. The left-hander restarted a rehab assignment that was scrapped in April. At that time, he was rehabbing from an internal brace procedure on his elbow but was set back by the biceps.