A month later:
https://www.mlbtraderumors.com/2021/09/red-sox-garrett-richards-bullpen-reliever-club-option.html
Since moving into a short-relief role, Richards has dominated. He’s tossed 20 2/3 innings of relief, pitching to a 0.87 ERA with a 29.4 percent strikeout rate, a 9.4 percent walk rate and a 48.1 percent ground-ball rate. Richards’ fastball averaged 94.2 mph out of the rotation, and that’s jumped to 95.0 mph in the ’pen — 95.3 mph since Sept. 1.
Richards has also seen gains in swinging-strike rate (from 9.4 percent to 10.8 percent), opponents’ chase rate (27.9 percent to 34.5 percent), opponents’ average exit velocity (91.6 mph to 89.4 mph) and an overwhelming drop in his opponents’ barrel rate — from 9.3 percent all the way down to 1.9 percent. Since moving to a relief role, he’s allowed just one “barreled” ball, as measured by Statcast, and he has yet to surrender a home run.