The Giants designated outfielder Tyler Graham for assignment, Henry Schulman of the San Francisco Chronicle tweets. The club placed left-hander Jeremy Affeldt on the disabled list and purchased the contract of left-hander Travis Blackley in corresponding moves.
Graham, 28, has yet to appear in the Major Leagues, but the Giants needed his 40-man roster spot to make room for Blackley. In seven minor league seasons, Graham has a .281/.341/.361 batting line with 222 stolen bases. He has spent most of the past four seasons at Triple-A Fresno.