10:30am: The Red Sox have officially announced the roster changes. Holt hits the 10-day IL with a scratched cornea in his right eye, while Johnson is placed on the 10-day IL with left elbow inflammation.
Walden, 30, made eight relief appearances for the Red Sox last season, giving up six earned runs in 14 2/3 innings (3.86 ERA). He joined the Red Sox as a minor league free agent prior to the 2017 season after stints with the Blue Jays, Reds, Twins and A’s organizations. Though most of his time in the minors has been as a starter, the Joe-Kelly-lookalike pitched primarily out of the bullpen for Pawtucket last year after missing most of June and July due to injury.
He’ll join a Red Sox bullpen that is second in volume usage thus far in 2019 with 33 2/3 innings of work. The unit is under the microscope this season after management chose not to resign back-end stalwarts Joe Kelly and Craig Kimbrel, the latter of whom, of course, remains available on the open market. The 8-man unit has held form thus far, striking out 10.69 batters per nine innings while stranding 77.4% of inherited baserunners.
Walden can help as a long man to bolster a rotation that has, meanwhile, absolutely cratered (to put it nicely). The unit as a whole is 0-7 in nine starts with a 9.60 ERA and -1.5 fWAR in a little over a week. Their 5.76 xFIP paints a slightly less face-melting picture, though even that number ranks dead last among starting units this season.
Infielder Tzu-Wei Lin is also being added to the 25-man roster, per Alex Speier of the Boston Globe (via Twitter). Lin started at least one game at shortstop, second base, third base and centerfield for the Red Sox last season. Brock Holt and Brian Johnson will land on the injured list as the corresponding roster moves, per Speier (via Twitter).