Sims allowed one walk over a scoreless two-thirds of an inning in Wednesday's 3-2 extra-inning win over Seattle.
Sims replaced starter Brayan Bello with one out in the seventh inning and runners at the corners. He sandwiched a walk around a short flyout and a groundout to get out of the inning. It was Sims' debut for the Red Sox, who acquired him ahead of Tuesday's trade deadline. Boston's bullpen has been the primary culprit of the team's 3-8 start coming out of the All-Star break, and Sims is expected to help. He'll be used in high-leverage spots ahead of closer Kenley Jansen, Julian McWilliams of The Boston Globe reports. The high-leverage crew will be bolstered by the eventual returns of Chris Martin (elbow) and Justin Slaten (elbow).