Shaw declined an outright assignment to Triple-A Worcester and elected free agency Sunday, Chris Cotillo of The Springfield Republican reports.
Shaw was designated for assignment by the Red Sox on Friday, Chris Cotillo of The Springfield Republican reports.
Shaw started at first base and went 0-for-3 in Monday's 3-1 loss to the Tigers.
Shaw went 2-for-2 with a double, an RBI and a run scored in Thursday's spring training game against the Twins.
Shaw signed a minor-league contract with the Red Sox on Friday that includes an invite to big-league camp, Alex Speier of The Boston Globe reports.
Shaw went 2-for-5 with a home run and four RBI in Saturday's 9-8 extra-inning win over the White Sox.
Shaw is out of the lineup for Monday's game against the Rays, Pete Abraham of The Boston Globe reports.
Shaw is not in the lineup Tuesday against the Rays, Julian McWilliams of The Boston Globe reports.
Shaw is not in the lineup Monday against the Rays, Ian Browne of MLB.com reports.
Shaw is out of the lineup for Sunday's game against Cleveland.