Here is a link about Giambi from PA SportsTicker. It does not mention Barton being called up.
I saw on MLB TV that Jason Giambi went on the 15 day DL today. To replace him on the 25 man roster the A's called up Daric Barton. Let us hope that Barton is here today and in the line up at 1B. Here is to hoping Daric stays up longer than 15 days.