"Rich came in today and said he wasn't quite as sore," manager Ken Macha said, adding that Hudson last year felt worse the day after his chronic injury resurfaced.
"It feels a lot better than I expected it to," said Harden.
Athletic trainer Larry Davis is reserving the right to change course again, though. Harden is scheduled for an MRI on Monday.
"Rich is a pretty intense guy," Davis said. "When you test him, he'll often test out better than he really is. You can't fool an MRI."
Harden's next turn in the rotation comes Wednesday against the Red Sox, and Macha strongly suggested that right-hander Keiichi Yabu will get the nod.
Lefty John Rheinecker would have been a candidate from Triple-A Sacramento, where he is 4-0 with a 1.77 ERA, but he recently developed a problem with a tendon in his left middle finger that takes him out of the mix.
Watson in, Clark out: In dire need of some punch at the plate, the A's called up outfielder Matt Watson, who was batting .345 with three homers and 20 RBIs in 35 games at Sacramento.
Watson was tied for the Pacific Coast League lead in hits (48), ranked third in runs scored (30), and was seventh in batting, and he's been a monster over his past 10 games, batting .512 (22-for-43) with 15 RBIs and two four-hit games.
"He's hot right now, and we could use a little sock in our lineup," said Macha, who started Watson in left field Saturday night. "He's been driving in runs and hitting for power."
"It's no secret we could use a surge of offense," assistant general manager David Forst said. "Every good at-bat helps at this point."
To make room for Watson, 26, the A's designated utilityman Jermaine Clark for assignment. Clark was hitting just .228 with 12 RBIs in 24 games at Sacramento when he was called up May 2, but Watson insisted that he wasn't discouraged when he was passed over in the wake of Nick Swisher's shoulder injury.
"I try not to figure out what they're thinking," said Watson. "Obviously, they felt that [Clark] fit their needs at the time, so I try not to second-guess what they're doing."
Clark, who was pulled off the field during batting practice, appeared in three games with the A's. He walked in his only plate appearance and scored two runs. If Clark clears waivers, he can turn down any assignment to the Minor Leagues and become a free agent.
"We'd like to do everything we can to keep him in the organization," Forst said.
Meyer shut down: Lefty Dan Meyer, the pitching prospect who came to Oakland as part of the Hudson trade with Atlanta, has what Forst called an "exhausted" rotator cuff and has been shut down indefinitely.
Davis, citing Meyer's limited range of motion, used the word "medieval" in describing the process by which the team will try to expand that range of motion. It basically involves Meyer laying on a table while someone wrenches his arm into places it won't go on its own.
"It's not pretty," said Davis, who added that Meyer has had shoulder problems since he arrived at Spring Training.
Though Forst said Meyer showed no signs of "pre-existing" shoulder trouble at the time of the trade, and he didn't pitch in winter ball, Meyer's velocity was down all spring, and he was 1-3 with a 6.62 ERA at Sacramento before he was shut down last week. There is no timetable for his return.
"We fully expect him to get back to being the guy we were pretty sure we traded for," Forst said.
Dribblers ...: Shortstop Bobby Crosby, on the DL with fractured ribs since Opening Day, will be working out with the A's through the current homestand, Macha said. He'll likely need a week to 10 days in the Minors before being activated. ... Swisher could be headed for a rehab stint soon, too. It's unclear where Crosby and Swisher will be sent, but if Sacramento is at home when they're cleared to play, that's where they'll go. ... Righty reliever Justin Duchscherer has a sore back and was unavailable Friday and Saturday nights.