The Red Sox have traded infielder Kevin Youkilis to the Chicago White Sox, major league sources told the Globe.
The Red Sox received 25-year-old righthander Zach Stewart and utility player Brent Lillibridge.
The Red Sox also will be picking up $5.5 million of the $6.6 million Youkilis has remaining on his contract for this season. The White Sox would be responsible for a $1 million buyout on a $13 million team option for 2013.
Stewart, 25, is a former third-round pick from Texas Tech who was once considered a hot prospect. But thisis the third time he has been traded in a span of four years, going from the Reds to Blue Jays and then to the White Sox and now to the Red Sox.
Stewart is 3-8 with a 5.92 earned run average in 31 career appearances, 12 of them starts. He was 1-2 with a 6.00 ERA in 18 appearances (one start) for the White Sox this season. He has thrown 30 innings, giving up 41 hits and striking out 16 with four walks.
The Reds traded Stewart, Edwin Encarnacion and Josh Roenicke to the Blue Jays for Scott Rolen at the 2008 trade deadline.
In 2011, again in July, he and Jason Frasor went to the White Sox for Edwin Jackson and Mark Teahen. Stewart could be developed as starter depth by the Red Sox.
Lillibridge, 28, is a career .215 hitter with the Braves and White Sox. He has played every position except pitcher and catcher.
Lillibridge will be reporting to the Red Sox with Stewart being assigned to Triple A Pawtucket.
To make room on the 40-man roster, the Red Sox designated Double-A left fielder Oscar Tejeda for assignment.