The move is a welcomed one for the 29-year-old Jackson, who plans to take his versatile abilities as a bench player over to a Red Sox team geared for the postseason.
"It's awesome," Jackson said following Oakland's 16-inning loss in Cleveland. "I don't think a guy in my position could ask for anything better, to go to a big-market team where there's probably the best fans in baseball.
"I'll probably have the same role, coming off the bench against lefties, but whatever it is I'll be grateful for it. I think the opportunity to play in October is unparalleled to anything else."
Jackson's role with the A's had quickly diminished in August, as a neck issue paved the way for the arrival of Brandon Allen, who has since assumed everyday first base duties once employed by Jackson. The outfield proved crowded, too, as manager Bob Melvin was having to shuffle Jackson in a right-field mix that already included David DeJesus and Ryan Sweeney.
The inconsistent playing time had an affect on Jackson, who left Oakland riding a career-long hitless streak spanning 21 at-bats.
"The fact that he gets to get the opportunity to go play in the pennant race in a place like that, I'm happy for him," said Melvin, who also managed Jackson in Arizona. "It's bittersweet, since I've managed him for several years. I've probably managed him longer than anyone else I've had, so in that respect it's disappointing. It's tough that he's gone, yet you have to be happy for him."
Jackson, who will be a free agent at season's end, is familiar with several members of the Red Sox, having worked out with Dustin Pedroia and Kevin Youkilis in previous winters. He was making $3.32 million this year, and the cash included in the deal is likely to offset his remaining earnings.
Rice, originally an 11th-round Draft pick by the White Sox in 2005, was 4-5 with a 3.69 ERA and four saves in 44 appearances with Triple-A Pawtucket. The right-handed reliever has 89 strikeouts through 85 1/3 innings this season.