Giants place Posey on 7-day concussion DL

The Giants placed Buster Posey on the 7-day disabled list with concussion symptoms Tuesday, a day after Posey was beaned in the head by a 94 mile per hour fastball.

Catcher Nick Hundley is expected to start in place of Posey against Arizona on Tuesday night. Tim Federowicz will be the team’s backup catcher after the Giants called him up from Triple-A Sacramento. Right-hander Clayton Blackburn was designated for assignment to make room for Federowicz.

In a scary moment during Monday’s Opening Day game at AT&T Park, Posey was struck on the side of his helmet by a Taijuan Walker fastball during the first inning. Posey sat up but was seemingly dazed, opening and shutting his mouth as if to take…