The Twins reinstated Stewart (hamstring) from the injured list Saturday, Phil Miller of The Minnesota Star Tribune reports.
Stewart has been on the injured list all season due to a left hamstring strain he suffered during spring training. He's made two rehab appearances in Single-A since then, pitching 1.2 innings and striking out every batter he faced. Now that he's fully healthy, the 33-year-old righty figures to immediately slide into a high-leverage role in Minnesota's bullpen. Kody Funderburk was optioned to Triple-A in a corresponding move.