The Yankees put Jorge Posada at first base on Thursday, a rare position for the long-time catcher. He has played in only 28 games at first base, including just 15 starts, and none since 2008. "It was very different," Posada said. "It's a process, especially with guys on base and double plays. It doesn't come instinctively to me. I have to think about it beforehand. I am like a fish out of water." Posada may not have to cover for regular first baseman Mark Teixeira if Eric Chavez can stay healthy. The catcher handled 12 chances without a mistake on Thursday.