San Francisco Giants backup catcher Hector Sanchez is expected to miss the remainder of the season while recovering from a second concussion this year. Sanchez returned Wednesday to AT&T Park after an examination by concussion specialist Dr. Micky Collins at the University of Pittsburgh and was instructed to rest for three weeks. Sanchez went on the concussion list July 26, then took a hard foul tip off the mask Aug. 16 while on an injury rehabilitation assignment with Triple-A Fresno, sustaining a second concussion.