"He's still feeling the effects of the initial impact, so at this point, I don't have a real good prognosis on when he will be back," general manager Sandy Alderson said. "At this point, as he exercises, he still experiences some symptoms. As a result, we're still in the recovery period."
In order to return, Alderson said, d'Arnaud must pass a post-concussion test, but the Mets will not ask him to do so until he is asymptomatic. Because d'Arnaud is on a specialized head-injury list and not the regular 15-day disabled list, Major League Baseball and the Players' Association must approve his return.
"We don't feel he's in a situation today where he should take that test," Alderson said. "Until he's feeling better, we won't run him through that testing."
In the interim, Anthony Recker and Juan Centeno will continue to split time at catcher.
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.