SAN FRANCISCO -- Acting quickly yet carefully, the Giants placed catcher Buster Posey on the seven-day concussion disabled list Tuesday, one day after a fastball from Arizona's Taijuan Walker struck him squarely on his batting helmet.
The timing potentially works favorably for the Giants. They could activate Posey in time for an Interleague series April 18-19 at Kansas City, where he would be eligible to perform as a designated hitter and ease himself back into the lineup.
"I don't anticipate it being a long time," said Posey, a four-time All-Star and San Francisco's cleanup hitter.
Posey's battery of tests included Major League concussion protocol. Giants general manager Bobby Evans said that Posey, 30, didn't have concussion symptoms Monday but displayed them Tuesday.
Posey said he had no headaches but felt "enough to know that something wasn't as normal. But I can tell there's nothing that I feel concerned about."
The Giants have learned through experience that concussion symptoms can linger dangerously.
First baseman Brandon Belt, second baseman Joe Panik and catcher Hector Sanchez, now with San Diego, all needed recovery time that was longer than initially expected. Panik actually resumed playing after being beaned by then-opponent Matt Moore of Tampa Bay last June 18, then went on the disabled list. Belt's case was so severe that the Giants sent him to a concussion specialist. And Sanchez's bouts with concussions are ongoing. He recently sustained his seventh, sending him to the DL.
Thus, the Giants felt compelled to facilitate Posey's return to health immediately.
"We feel like we have a better chance of getting him back sooner if we exercise caution right now," Evans said.

Posey indicated he'll rest completely for at least two days before resuming physical activity.
Walker insisted he wasn't purposely throwing his 94 mph fastball at Posey, who absolved the right-hander from blame.
"I never thought he was trying to hit me," Posey said. "It was a bad miss, but I never thought he was trying to hit me."
The Giants replaced Posey on their active roster by purchasing the contract of catcher Tim Federowicz from Triple-A Sacramento. Federowicz, a non-roster invitee to Spring Training, made a positive impression while batting .323 in 21 exhibition games. He also hit .222 (2-for-9) at Sacramento. Trevor Brown would have been called up under ordinary circumstances, but he's still recovering from an ankle injury.
"We're going to miss Buster," Giants manager Bruce Bochy said. "But it's good to have depth."
The Giants soon might have a little less pitching depth. To clear a 40-man roster spot for Federowicz, they designated right-hander Clayton Blackburn for assignment. Just two years ago, Blackburn led the Pacific Coast League with a 2.85 ERA.
"I think it'll be hard to retain him because he has a lot of value on the market," Evans said.