Yankees manager Aaron Boone said Thursday that Hamilton (groin) will be out for approximately four weeks, Erik Boland of Newsday reports.
Hamilton was enjoying a breakout season before landing on the 15-day injured list Wednesday with a right groin strain. He holds a 1.23 ERA and 1.09 WHIP through 22 innings and is now looking at an extended stay on the IL. In Hamilton's absence, the Yankees will likely turn to Ron Marinaccio and Jimmy Cordero more often in high-leverage relief situations.