Harden, nursing a sore lat muscle back to health, threw 20 pitches in the session and fielded nothing but good reports from his spectators, including a new one from interim skipper Bob Melvin.
"He looked good to me," Melvin said. "I know he had a little setback, but it was good to see him out there feeling good about himself.
"The Rich Harden that I know is that guy who sneaks the ball by the hitters and it's got that little wrist pop for the last 15 or 20 feet, where the ball explodes. You were certainly seeing that today, with some of the swings the hitters were taking. That was encouraging to see."
The A's will of course continue to be cautious with Harden, who has yet to pitch in a game this season and has a long history of injuries, evidenced by his 10 career stints on the disabled list. But as long as there continue to be no more setbacks with the proven right-hander, the A's will seek his help down the line as they try to offset numerous injuries to their starting staff.
"Here's a pitching club that relies on its pitching, so that dynamic plays into what's going on here," Melvin said. "You see someone who's getting close, someone who could have an impact, I think everybody feels good about that."