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05/09/12 12:12 AM ET

Thole on seven-day DL with concussion

PHILADELPHIA -- Feeling lingering dizziness the day after a home-plate collision, Mets catcher Josh Thole was placed on the seven-day disabled list Tuesday with a concussion. The team recalled Rob Johnson from Triple-A Buffalo to replace him.

Though his DL stay must last at least seven days, Thole may miss significantly more time than that after his collision Monday with Phillies first baseman Ty Wigginton. General manager Sandy Alderson said Tuesday that Thole will not perform any athletic activities for at least seven days, after which point the Mets will reevaluate his condition.

"Based on what we know now, I don't expect him back after seven," Alderson said, referring to Thole's history of multiple concussions earlier in his professional career."

Thole ultimately walked off the field under his own power Monday after several motionless minutes on the ground, but he experienced dizziness and hot flashes after the game. In good spirits the next day, Thole was still experiencing dizziness, prompting the Mets to send him back to New York for further examination.

Those tests revealed his concussion. Major League Baseball instituted a seven-day DL last year for head injuries, which nearly a dozen players have used since its inception. The Mets can keep Thole on that list until he is ready to return to active duty.

"It seems like it's the way it has been here for a while -- you lose key guys," manager Terry Collins said of the recent run of injuries afflicting the Mets. "No matter who sits in this chair, you've got to put somebody else in there and hope guys pick up the slack."

That somebody will initially be Mike Nickeas, who hit a key double Monday in Thole's stead. But Johnson, an MLB veteran who was hitting .291 with two home runs in 15 games for Triple-A Buffalo, will also receive significant playing time. Even before knowing the full scope of Thole's injury, Collins was making plans to insert Johnson into the lineup Wednesday against Phillies left-hander Cliff Lee.

The hope is that Johnson and Nickeas can at least approach the production of Thole, who has reached base safely in all but three of his 26 games this season. Though the catcher had cooled somewhat after a torrid start, Thole was batting .284 with a .356 on-base percentage prior to his injury.

Thole's greatest lament, Collins said, was that he did not keep his catcher's mask on in preparation for the collision with Wigginton. But Collins and others around the team viewed the injury as an unavoidable occupational hazard.

"We've all been crushed," said Nickeas, one of Thole's close friends. "You get guys coming into you hard, and hopefully it just gets you in the right spot and you're able to absorb the impact. But Josh kind of got clocked."

To make room on their 40-man roster for Johnson, the Mets transferred reliever Pedro Beato to the 60-day DL.

Playing time hard to come by for Valdespin

PHILADELPHIA -- A day after Jordany Valdespin delivered a game-winning, three-run home run for his first Major League hit, manager Terry Collins was blunt about Valdespin's chances to remain in the Majors for any extended period of time, even with Ruben Tejada on the disabled list.

"It would be hard for him to do that," Collins said. "Not that he can't. But I'm not sure we really have enough time to get him in there that much."

Valdespin's issues are two-fold. Because the Mets face left-hander Cliff Lee on Wednesday, Justin Turner is scheduled to start that game at shortstop instead of Valdespin. And because regular shortstop sub Ronny Cedeno is due back from the disabled list Friday, there is a crunch for playing time at the big league level.

More than anything, Collins wants Valdespin to amass playing time at his young age, be it in the Major or Minor Leagues.

Even so, Valdespin's second stint in the Majors is already guaranteed to be a memorable one. Following Monday's game-winner, local fan Marty Wixted saw on television that his son had caught Valdespin's home run ball. Wixted called up the Mets, who offered to bring him and his four children back to Citizens Bank Park on Wednesday in exchange for the ball.

Worth noting

• After an examination Tuesday by doctors in New York, shortstop Ruben Tejada was cleared of any concussion-related issues stemming from his stumble over the first-base bag in Sunday's game. The Mets placed Tejada on the disabled list Monday with a strained right quad, and fully expect him to return when eligible on May 22.

• Monday's victory was the Mets' 400th all time against the Phillies, their most against any Major League team. The Mets are 400-459 against the Phillies in their history.

Anthony DiComo is a reporter for MLB.com. Follow him on Twitter @AnthonyDicomo. This story was not subject to the approval of Major League Baseball or its clubs.