The talented right-handers for the AL's two top teams will miss their next turn, both scheduled for Friday, the day after Boston and Detroit finish a four-game series with a day-night doubleheader. That was caused by a rainout Wednesday night.
Beckett, baseball's winningest pitcher at 7-0, has a torn flap of skin that hasn't completely healed. Bonderman, who had two blisters in spring training, went on the Tigers' disabled list Wednesday, retroactive to May 9, with a blister, making room for Andrew Miller, Detroit's first-round draft pick last season, to make his major league starting debut.
Bonderman (2-0) leads the Tigers with 40 strikeouts in 45 innings but missed his start last Sunday. He has thrown on the side since then and is eligible to come off the disabled list May 24 when Detroit plays the Los Angeles Angels.
"When he threw the other day he said he felt pretty good. I don't see it being a (long-term) problem," Tigers designated hitter Gary Sheffield said. "Beckett has had it a few times and he deals with it a lot, but he seems to go out and make his starts."
With Florida in 2002, Beckett's first full season in the majors, blisters on the middle finger sent him to the disabled list three times. In 2004, he made three more trips to the disabled list -- once with a blister on the middle finger, another time with a cut on that finger and a third time with a strained lower back.
He stayed off the list last season, his first with the Red Sox, and is having the best early season of his career this year. He won his first seven starts then left last Sunday's 6-5 win over Baltimore after four innings.
Beckett is "doing very well, very well," manager Terry Francona said, and will throw a side session before Friday's game against Atlanta.
"Missing him for a start isn't a lot of fun so you start multiplying that, we don't really want that to happen," Francona said. "So I think being cautious is the right thing to do. I know it is."
The Red Sox starting pitchers haven't missed a start because of injury all season, helping them build a large lead in the AL East. The rotations of division rivals New York Yankees, Toronto and Baltimore haven't been as fortunate.
Julian Tavarez will start Thursday afternoon against Detroit's Mike Maroth in the same matchup that was set for Wednesday night. Boston's Curt Schilling faces Chad Durbin in the second game.
"The main thing is staying healthy," Tavarez said, "keep our starting pitching healthy, our bullpen and the position players and you will see in October we will be in the World Series. If everybody stays healthy, there's no doubt we have everything we need out here."
Francona said a pitcher currently at Triple-A Pawtucket would start in Beckett's place in the opener of a three-game home series against Atlanta. Possibilities include righty Devern Hansack, who spent a few days with the Red Sox this season, and lefty Kason Gabbard.
Bonderman's replacement will be Miller for Friday night's game against St. Louis, manager Jim Leyland said. He made eight relief appearances for the Tigers last season and has spent time this season at Single-A Lakeland and Double-A Erie.
"We need him to come down, just make sure he throws strikes and doesn't (try) to do too much," Detroit catcher Ivan Rodriguez said. "He has a lot of talent to be a great pitcher in this game, but at the same time he's very young and he's still learning."
Francona said lefty starter Jon Lester would begin another rehab assignment Saturday when he pitches for Pawtucket in Ottawa. Lester, coming back from cancer diagnosed last season, suffered a cramp in his throwing arm in the last outing of his previous rehab assignment.
The Red Sox also were dealing with a back injury suffered by right fielder J.D. Drew on Tuesday night when he crashed into the low wall trying to catch Brandon Inge's homer in Detroit's 7-2 win.
Drew was not in the starting lineup before Wednesday night's game was postponed.
"He checked in this morning and said he was doing pretty well," Francona said. "He got to the ballpark and said, 'I don't feel any worse now than when I left the game (Tuesday) night.' So I think that's encouraging."
He said he didn't know if Drew would play Thursday.