10:58am: The Red Sox tried to remove the player to be named later from the deal and just send Anderson after looking at Harden's medicals, and were rebuffed by the A's, tweets Sean McAdam.
SUNDAY, 1:05am: Uncertainty after a review of Harden's medicals led to the deal coming apart, tweets Speier.
12:36am: A major league source says that the BoSox are not counting on the deal getting done, according to Alex Speier of WEEI.com.
SATURDAY, 11:47pm: A's GM Billy Beane told Harden he's still scheduled to pitch for the A's Tuesday, according to Slusser (on Twitter).
8:20pm: It looks as though the Red Sox are closing in on a deal for Rich Harden, according to ESPN.com's Jayson Stark on Twitter. ESPN's Buster Olney reported on the deal earlier today and Susan Slusser of the San Francisco Chronicle reported tonight that there was a "strong chance" of a deal.
Harden, 29, has a 4.30 ERA with 9.2 K/9 and 3.1 BB/9 in 29 1/3 innings for the A's this year. The British Columbia native was on the disabled list until the beginning of July. He earns a $1.5MM base salary this year.