Shaw declined an outright assignment to Triple-A Worcester and elected free agency Sunday, Chris Cotillo of The Springfield Republican reports.
Shaw secured a spot on Boston's Opening Day roster but was designated for assignment Friday after going 0-for-19 with seven strikeouts to begin the campaign. The veteran infielder will hope to latch on elsewhere, but he'll likely need to settle for a minor-league deal given his .616 OPS and 29.8 percent strikeout rate over the past three seasons.