MINNEAPOLIS -- Andrew Bailey underwent a successful bullpen session Sunday morning and could possibly be activated from the disabled list on the A's homestand this week, manager Bob Geren said.

Bailey, nursing a strained rib cage muscle back to health, played catch from a distance of 120 feet before throwing all of his pitches in a bullpen he deemed he "dominated."

"No hits allowed," Bailey said with a smile.

That's good news for the A's, who hope to have their closer back on the upcoming seven-game homestand against Toronto and Tampa Bay that begins Monday. If Bailey experiences no ill effects from Sunday's session, he said he'd likely throw one more bullpen before potentially pitching in a simulated game and being activated thereafter.

"He needs a couple more times off the mound," Geren said. "But, today, obviously was a big step. Him throwing off the mound at that kind of effort level, that's a real positive step.

"We're optimistic based on how he feels right now."

Bailey hasn't pitched since July 20, a time when he had not allowed a run in 13 of his past 15 appearances.

A's look forward to Jackson's return

MINNEAPOLIS -- A's manager Bob Geren may be facing quite the decision this week upon returning to Oakland for a seven-game homestand, when rehabbing outfielder Conor Jackson could potentially return from the disabled list.

Jackson (right hamstring) was slated to play in his third rehab game with Triple-A Sacramento on Sunday, when Geren said "it's possible" he could be activated this week. In his previous two contests with the River Cats, he went 0-for-8 with a walk and strikeout as the starting left fielder. He also appeared in two games with Class-A Stockton and three with the A's Arizona Rookie League team.

Once activated, Jackson will likely be inserted back in left field, where the newly promoted Chris Carter has been playing this week. Geren wouldn't go so far as naming Jackson his everyday left fielder, but he did say Jackson is "an everyday player, a good player."

Before his DL stint, Jackson was batting .267 (12-for-45) with four RBIs in 14 games for the A's.

"He'll play a lot," Geren said. "Whether it's every day or not, we don't know. He's been off for a while, and we want to make sure he's healthy.

"When Conor comes back, we'll talk about the rest of the guys."

Carter, Oakland's highly touted power prospect, has started all six games since his Monday callup and entered Sunday's contest against the host Twins hitless in 16 at-bats with seven strikeouts and a walk.

"He hasn't got a lot to hit," said Geren, who spoke to Carter in passing Sunday morning. "His confidence is not shaken in any way. He's a very confident young man. He's had success at every level in his career, and I'm sure he'll continue that here."