Garciaparra still has swelling in his right wrist after being hit by a pitch on Friday, although club officials are still confident the injury is a bruise and not a break. Garciaparra had surgery near the point of impact in 2000.
Sweeney had fluid drained from his left knee a week ago. The long flight to China, coupled with his need to see playing time, were reasons the club gave for his withdrawal. Minor League infielder Kevin Howard was named as a replacement, meaning Andruw Jones will be the only true veteran making the trip. Young outfielder Matt Kemp also is on the travel squad.
In pitching news, the Dodgers trimmed their staff by releasing Martin and reassigning young right-handers Mario Alvarez, James McDonald, Jon Meloan and Justin Orenduff.
They also added young third baseman Blake DeWitt to the Major League camp to provide depth with injuries to Andy LaRoche (out two months with thumb surgery), Tony Abreu (lingering abdominal discomfort) and Garciaparra. Dewitt started Monday's game against the Orioles, his second start in three games.
The 37-year-old Martin, essentially in a head-to-head competition with Mike Myers for the second lefty reliever spot behind Joe Beimel, had a 4.91 ERA and allowed seven hits in 3 2/3 innings. Myers, 38, hasn't allowed a run in four innings. Myers previously pitched for manager Joe Torre in New York.
McDonald made his spring debut Sunday with a scoreless inning after missing a week with a tired arm. Meloan, who received a September callup last year, had command problems this spring.
The club has 54 players in Major League camp, including 19 pitchers.
Ken Gurnick is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.