While Posada is a valuable Core Four guy, he is not invaluable. The Yankees are better with him -- far better, really -- but they can survive without him.
They have done it recently. In 2008 and 2009 combined, the Yankees were an incredible 74-42 with Posada. That is a .698 winning percentage. With his backups, they were 118-90. A very respectable .567 winning percentage.
A .121 percent difference shows what Posada's bat means to the Yankee lineup, but the Yankees are better defensively and the pitchers are happier when Francisco Cervelli is behind the plate. They, of course, won't say it publicly -- especially Thursday's starter, controversy-shy A.J. Burnett -- but they largely prefer to throw to Cervelli.
So far this season, Cervelli has answered questions about if the league will catch up with him at the plate. He added two more hits in Posada's place on Wednesday and is now hitting a pristine .444 on the season. Every time Cervelli steps on the field, he gives the Yankees more confidence in him.
Last year, Posada missed 22 games with a strained hamstring, and the Yankees didn't miss a beat. They were 14-8 with a 4.03 ERA in those games. Cervelli was discovered and Jose Molina eventually ended up in Toronto.
In the second inning of Wednesday night's Yankees win, there were ideas that Cervelli could be called for extended duty again.
Ineffective Orioles starter Jeremy Guthrie fired a 94-mph scorcher off Posada's knee. Posada winced as he walked around the batter's box. Joe Girardi -- who was "frustrated" by Guthrie's lack of control -- and trainer Steve Donohue escorted him down to first, asking him if he needed to be removed. Posada indicated he felt fine.
After moving to second, he even scored -- laboring the whole way -- on Nick Swisher's two-run triple.
"The worst part was seeing him run around the bases because his grimace was so bad," Core Four member, Andy Pettitte said.
When he returned to the dugout, Posada told Girardi he was done. He doesn't think the contusion on his right knee is going to be a DL situation, but he doesn't know for sure.
Teams -- and the Yankees are no different -- generally downplay injuries. As of Wednesday night, though, the Yankees had no plans to send Posada for X-rays. That could quickly change, depending how Posada feels when he wakes up.
"I have no idea how it will feel," Posada said.
He will almost definitely not play on Thursday, Girardi said. Prior to Wednesday's game, Girardi planned to give Posada one of the next two games off.
Posada may not be a Hall of Famer, but he is a legendary Yankee. He will rightfully be remembered for his consistency; especially at the plate. The Yankees think his injury is not too serious and he will return soon.
They can survive losing Posada in the short term. And if it turns out to be more serious? The Yankees don't have that answer.