Duchscherer was placed on the 15-day disabled list, retroactive to Wednesday, because of a pain in the same hip on which he had surgery last summer. A's manager Bob Geren said inflammation in the joint is why Duchscherer left his last start in the third inning at Minnesota on Monday.
Oakland also placed right-handed starter Sean Gallagher on the 15-day DL, also retroactive to Wednesday, due to shoulder fatigue.
The A's, who entered Thursday's series opener at Seattle having lost 18 of 22 games, have used the disabled list 23 times this season. That is once more than the previous Oakland record of 22 set in 1992 and matched last season.
The A's recalled left-handers Dana Eveland and Dan Meyer from Triple-A Sacramento to join the rotation. Eveland, in his second stint with the A's this season, is scheduled to start on Saturday. Meyer is scheduled to pitch Sunday. He is also in his second stint with Oakland this year.
The team now has an all left-handed, five-man rotation -- including Thursday's starter Greg Smith, Gio Gonzalez and Dallas Braden. The only other time Oakland has had an all-southpaw rotation was in 1973 with a four-man staff of Vida Blue, Ken Holtzman, Darold Knowles and Paul Lindlad.
It's a good weekend for the A's to have one. Seattle, the worst team in the AL, entered the four-game series a major league-worst 12-26 against left-handed starters.
Duchscherer received treatment in the Bay Area on Thursday to begin his second stint on the DL this season, and fourth in the last three years. He is 10-8 with a 2.54 ERA in 22 starts. His ERA is the second lowest in the major leagues, but he needs 20 1-3 more innings to qualify for the league leaders at the end of the season.
Geren is optimistic Duchscherer will get that chance to qualify soon.
"It's possible he'll pitch again in a couple of weeks," the manager said. "He's optimistic."
Geren sounded less optimistic about Gallagher, acquired from the Chicago Cubs in the trade involving Rich Harden on July 8. Gallagher gave up a career-high 10 runs in five innings against Minnesota on Tuesday, then said he had no pain but that "the ball felt like a feather" and he didn't have any strength when he threw.
"Hopefully," is all Geren would say when asked if Gallagher will pitch again this season.