Olerud, 37, was an All-Star in 1993 and 2001 and a .295 career hitter with 255 home runs and 1,230 RBI in 2,234 games. He has played for Toronto (1989-96), the New York Mets (1997-99), Seattle (2000-04) and the Yankees (2004). He won Gold Gloves in 2000, 2002 and 2003.
Olerud won the AL batting title in 1993 with a .363 average and helped Toronto win its second consecutive World Series title.
He had surgery in November to repair torn ligaments in his foot and was on crutches until January. He signed a minor-league deal with the Red Sox on May 1 and went from extended spring training to a minor-league rehab.
He batted .289 in 87 games for Boston last year.