SCOTTSDALE, Ariz. — When the San Francisco Giants line up on Great American Ballpark’s third-base line on March 27, Tom Murphy likely won’t be among the 26 players in uniform.

Backup catcher Tom Murphy is likely to miss Opening Day for the San Francisco Giants with a herniated disk in his back. Murphy, 33, had been sidelined with an oblique injury since the first week of spring training for which he got a second opinion late last week.

San Francisco Giants backup catcher Tom Murphy is in danger of missing Opening Day with a herniated disc in his back that required an epidural injection.

Bob Melvin has yet to tell Logan Webb that Webb will be the ’ Opening Day starter. Melvin understands he doesn’t really need to have that conversation with his ace. “He knows,” Melvin said with a smile.

It was a safe assumption. This will be Webb’s fourth consecutive Opening Day start, matching the longest streak in Giants history since Juan Marichal started six consecutive openers in the 1960s. Madison Bumgarner made a total of five Opening Day starts over a six-year span; Tim Lincecum started four consecutive openers from 2009-12.