OAKLAND -- The A's have gone through several discouraging stretches this season in which they seemed to be absorbing mental blows daily. They've already used the disabled list 13 times, and as the list grew, so, too, did a quiet sense of frustration.

"Don't get me wrong -- the guys have had a great attitude all along," A's manager Bob Geren said. "But sure, after a while, it's bound to weigh on you a little bit."

Wednesday, however, brought the return of Milton Bradley, and Friday will bring with it the return of fellow outfielder Mark Kotsay. There remain too many key players on the DL to say the tide is turning for the A's, but at least it's been temporarily stemmed.

"It's great," Geren said before the finale of a three-game series against the visiting Rangers at McAfee Coliseum. "Just writing Milton's name in the lineup today made me smile, and when he's at the plate during the game, everyone in the dugout just has a good feeling that something positive is about to happen

"Then we get a day off [Thursday], and here comes Kotsay on Friday."

Bradley, who was on the DL with a left hamstring strain, started in center field and batted cleanup. Kotsay, who has been on the DL all year in the wake of March back surgery, will start in center field Friday and bat first or second, with Bradley likely to slide over to right field.

"We're a better team now," Geren said. "We're getting some great Major League players back, and the whole atmosphere will be more upbeat as a result. It's a huge boost, mentally and physically."

The mental impact of Kotsay's return is particularly significant. He's an established clubhouse leader, and while not a rah-rah guy by any stretch, he's one of the team's most vocal players in the dugout.

"On the field, the entire outfield will be better with him in the middle of it," Geren said. "And he's an outgoing, boisterous personality on the bench. Everything about him coming back is positive."

Unless, perhaps, your name is Jack Cust or Travis Buck. The journeyman designated hitter and rookie outfielder likely will see their playing time cut considerably once Bradley and Kotsay get past the handle-with-care stage of their respective returns. Geren said he'll resist the temptation to play Bradley and Kotsay every day for the time being.

Buck was in the lineup Wednesday, but he probably won't be Friday if Bradley and Kotsay start. Shannon Stewart is the everyday left fielder, and Wednesday's lineup featured a look that could end up being a fixture: Nick Swisher at first base and Dan Johnson at DH, with Cust, mired in a 3-for-30 slump, on the bench.

"Everybody in that outfield-DH-first base mix is going to need days off here and there, so there will be opportunities for everyone," Geren said. "Maybe not as many for some guys, but the bottom line is that it'll be good for the team, and everyone's on the same page with that.

"I don't really see it being a problem at all."

Boca bounced: Outfielder Hiram Bocachica, who has been in the A's organization since the start of the 2005 season and made big-league cameos each year, was the odd man out when Bradley was activated. He was designated for assignment, which means the A's have 10 days to trade him, release him or outright him to the Minors.

"I'm not surprised. They have a lot of good outfielders and I just got here," said Bocachica, who was released by the A's this spring only to re-sign with the club a few days later. "I knew there was a good chance of it being me, but it always hurts. I've been around long enough to know how this business works, and we'll see what happens in 10 days."

If not traded or released, Bocachica, 31, must be placed on waivers at some point during that 10-day span. If he isn't claimed within 72 hours, he can re-sign with Oakland.

""We're hoping he'll come back with us," Geren said. "Boca's a great guy, and he's a talented player. ... And the way things have gone with our outfield situation, you never know. Maybe there'll be another opportunity for him."

Dribblers: Second baseman Mark Ellis, who has a swollen knee, was held out of the starting lineup for the second consecutive game. He's day-to-day, and so is his wife, Sarah, who is due to deliver the couple's first child Thursday. ... Closer Huston Street, on the DL with nerve irritation in his right elbow, said he still can't completely straighten his arm and doesn't expect to start playing catch again until late this weekend at the earliest. ... Some of Oakland's starting pitchers have started getting in some cuts in preparation for more Interleague Play. Geren wants them to hit soft toss or off a tee a few times before they take part in batting practice on the field. "The main thing we want them to focus on, obviously, is bunting," Geren said. "We don't need any oblique strains 'cause someone's trying to go yard up there." The A's play in San Francisco next weekend, with Chad Gaudin, Dan Haren and Lenny DiNardo the probable starters for the series. ... Haren, who pitched Wednesday, will be kept on turn despite Thursday's off-day. So he'll work Monday in the opener of a four-game series against the visiting Red Sox, with DiNardo being pushed back to Tuesday, giving him six days of rest between starts to Haren's standard four. ... Righty David Shafer, designated for assignment last Friday, cleared waivers and has been assigned outright to Sacramento. ... The A's also announced that they have acquired outfielder Dee Brown from the Diamondbacks in exchange for cash considerations. Brown was batting .282 with two homers and 24 RBIs in 41 games with Triple-A Tucson.

Up next: A's lefty Joe Kennedy (1-4, 3.62 ERA) will get the ball Friday opposite Twins righty Kevin Slowey, who'll be making his big-league debut in the opener of a three-game series here. The first pitch is set for 7:05 p.m. PT.