Guerrero has a torn muscle in his chest and was placed on the 15-day DL before Friday's game at Minnesota.
Manager Mike Scioscia said Guerrero would be re-evaluated again in a month.
YANKEES: Hideki Matsui 's surgically repaired left knee has filled with fluid, causing the team to recall first baseman Juan Miranda from Scranton/Wilkes-Barre.
BLUE JAYS: Catcher Michael Barrett left Friday's game against Oakland in the fourth inning after he injured his right shoulder chasing a wild pitch.
ROYALS: Third baseman Alex Gordon is expected to be out for at least two months after having surgery to repair a torn labrum in his right hip.
RED SOX: Manager Terry Francona said Justin Masterson will start Monday's annual Patriots' Day game at Fenway Park, replacing Daisuke Matsuzaka , who has been place on the DL with shoulder fatigue.
TWINS: Claimed pitcher Juan Morillo off waivers and designated Philip Humber for assignment.