Littell's contract was selected from Triple-A Worcester on Saturday, Christopher Smith of The Springfield Republican reports.
The 27-year-old righty had a 3.82 ERA and 102 strikeouts in 106 innings for the Giants from 2021 through 2022, but he'd been working as a Triple-A reliever for the Rangers prior to getting shipped to Boston for cash. Littell should work in low-leverage spots.