"It just set the whole thing back," Berkman said. "The muscle that comes over the knee doesn't have enough strength now. It just needs to get stronger. As far as how long it set it back, I don't know. It's not like I just got hurt again. It's certainly stronger than that. But it's not where it needs to be."
Berkman played through the instability, but it was obvious when his knee gave out on him during his final at-bat on Thursday that rest and rehab would be the only way to properly allow his knee to heal.
"I have to get it strong," said Berkman, who has gone 2-for-11 since being hit by that Kershaw pitch. "It's hard to get the kind of work that you need to do and play at the same time because you have to exhaust it."
That strength work begins immediately for Berkman, who has spent more time off the field in 2012 than on it. A year removed from earning Comeback Player-of-the-Year honors, Berkman missed most of the season's first half with a left calf strain and then a right knee injury.
He's accrued a total of 75 at-bats, but hit just .133 in the 33 since returning from knee surgery. Getting the stability he's needed to swing right-handed has particularly been an issue.
"It's been frustrating," Berkman said. "Baseball season is so much about getting into a good rhythm, getting into a good routine. My goodness, if you would have told me that I'd have two homers and seven RBIs in late August, I would have laughed at you. I don't know what else to do about it. You just show up and try to get it ready to go."
The Cardinals do have the luxury of moving on without taking a substantial hit from Berkman's absence. Allen Craig will handle the majority of playing time at first base. And assuming Berkman does return this season, he'll provide manager Mike Matheny a potent bat off the bench.
As for his baseball future (and if there will be one) beyond 2012, Berkman isn't ready to address that just yet. He is not signed beyond this season.
"Those are the kind of questions that I'm trying to put off until the offseason," Berkman said. "It's hard to make a good decision about that thing while you're in the middle of kind of going through the thing. Those are better analyzed in the perspective of the offseason and seeing how the rest of the year goes. We'll just see what happens."