To make room for both on the roster, the team optioned infielder Kevin Youkilis to Triple-A Pawtucket while outrighting right-handed reliever Scott Cassidy, also to the PawSox.
Schilling has missed the last 69 games with a right ankle bone bruise and made five rehab appearances with Pawtucket, the first two outings as a starter and the last three as a reliever. He posted no record and a 3.00 ERA (1 ER/3.0 IP) in the three relief outings, walking none, striking out four and limiting opponents to a .231 batting average out of the bullpen. He went 0-1 with a 5.40 ERA (6 ER/10.0 IP) in his two rehab starts.
Schilling began the 2005 campaign on Boston's 15-day disabled list rehabilitating from right ankle surgery and was activated April 13, going 1-2 with an 8.15 ERA (16 ER/17.2 IP) in three starts before returning to the disabled list on April 29 (retroactive to April 24).
Bradford, who is signed through this season, hasn't pitched for the A's in 2005 after having surgery in March to address painful spasms in his lower back. The trade cannot be announced or become official until Bradford is activated from the 60-day disabled list.
Bradford, who has pitched for four playoff teams, has a career 21-15 mark with a 3.47 ERA in 294 games. Payton, who was unhappy with his backup role in the Red Sox outfield, hit .263 with five homers and 21 RBIs in 55 games this year.
Like Youkilis, Bradford was one of the prominent characters in Michael Lewis' book, Moneyball, and was an integral bullpen piece of Oakland's run to AL West titles in 2002 and '03 and the AL Wild Card in 2001.
He also contributed to the 2000 AL Central Division Champion White Sox before being traded to the A's prior to the 2001 season for catcher Miguel Olivo.
In 294 Major League relief appearances, the 30-year-old Bradford has limited righties to a .220 batting average while posting an ERA of 3.11 or less in four of his last five campaigns. The 6-foot-5, 203-pounder has 206 strikeouts and just 87 walks in 296 innings, a 2.4 strikeout-to-walk ratio.
Bradford has made at least 68 appearances in each of his last three seasons with Oakland, including a career-high 75 outings in 2002 and 72 appearances in 2003. In eight postseason appearances with Chicago (2000) and Oakland (2001-03), he has not allowed a run in 8 1/3 innings.
Bradford went 5-7 with one save and a 4.42 ERA in 68 outings for Oakland last season, limiting right-handers to a .211 batting average. He has combined to post a 3.24 ERA in nine appearances this season during his rehab assignment in Oakland's Minor League system.
Youkilis batted .286 (27-for-63) with one home run and nine RBI in 31 games for Boston while Cassidy made one relief appearance for the Sox, allowing three runs on four hits Saturday at Baltimore.