Loaiza is 1-2 with a 6.93 ERA over his past four starts and his ERA ranks seventh highest among American League pitchers with a minimum of 55 innings pitched.
The right-hander is 3-2 with a 4.70 ERA against the Red Sox. In his last start against Boston, the right-hander gave up seven runs over 4 2/3 innings on September 26, 2004.
BOS: LHP Jon Lester (4-0, 3.06 ERA)
OAK: RHP Esteban Loaiza (3-5, 6.43 ERA)
In his last start, Loaiza tied a career high by giving up four homers (all solos). He left after 5 1/3 innings against the Angels and gave up four runs on eight hits.
The 22-year-old has won four of his last five starts after making his Major League debut on June 10. In his last start, Lester held the White Sox to two runs on six hits over six innings.
Player to watch:
David Ortiz is 11-for-26 against Loaiza with three RBIs.
On the Internet
Official game notes
KYCY 1550 AM and KNTS 1220 AM
Friday: Athletics (RHP Dan Haren, 6-7, 3.52 ERA) at Red Sox (RHP Josh Beckett, 11-4, 4.75 ERA)
Saturday: Athletics (LHP Barry Zito, 8-6, 3.29 ERA) at Red Sox (RHP Curt Schilling, 10-3, 3.60)
Sunday: Athletics (RHP Joe Blanton, 8-8, 4.95 ERA) at Red Sox (RHP Tim Wakefield, 7-8, 4.05 ERA)
Ryan Quinn is an associate reporter for MLB.com This story was not subject to the approval of Major League Baseball or its clubs.