MILWAUKEE -- The Brewers received right-handed reliever Fautino De Los Santos from the A's on Sunday to complete a trade that sent catcher George Kottaras to Oakland.

Brewers assistant general manager Gord Ash had been seeking a Major League landing spot for Kottaras since the Brewers designated him for assignment on Thursday, opting to keep the young Martin Maldonado as the backup catcher instead.

"My time in Milwaukee was memorable," Kottaras told fans via his Twitter account. "Great city. Great fans. Made a lot of friends. Gonna miss it."

De Los Santos, 26, was optioned to Triple-A Nashville. To make room for him on the 40-man roster, the team shifted right-hander Shaun Marcum to the 60-day disabled list.

De Los Santos, 26, has a 4.21 ERA and 46 strikeouts in 36 1/3 innings for the A's over the past two seasons, including 34 appearances in 2011 and six this year. Big league opponents batted only .220 against him last season but were 7-for-17 in very limited duty this April.

De Los Santos had been at Triple-A Sacramento since then, pitching to a 7.25 ERA and a .320 opponents' average in 28 games. He had been pitching well in July before allowing three hits, a walk and three earned runs on Tuesday at Salt Lake City. He has not pitched since then.

"He's got big velocity and has struggled at times with his command, but in a deal like this, it is a chance to get an upside arm," Ash said. "[The A's] had expressed interest [in Kottaras] and we gave them a couple of names, and this was one we agreed on. Our scouts saw him and liked his arm; I know he hasn't had great results this year, but there's some upside."

De Los Santos will be out of options beginning next year.

Thornburg optioned by Crew to be stretched out

MILWAUKEE -- Although Brewers pitcher Tyler Thornburg was optioned to Triple-A Nashville after Sunday's 11-10 loss to the Nationals in 11 innings, the 23-year-old right-hander can take solace in the fact he likely won't be there for long.

"We want to get this guy back starting and get him back in a routine where we feel like we can push him forward," Brewers manager Ron Roenicke said. "And we'll probably see him later on somewhere starting for us, whether it's September or whether it's before that. But we want to get him back pitching like we know he can in a role that may suit him a little bit better."

The Brewers did not immediately make a corresponding move, but Roenicke confirmed that the club would call up a reliever before Monday's series opener against the Astros.

Thornburg, who has started 14 games in the Minor Leagues this season, made three appearances with the Brewers out of the bullpen this month, allowing two runs in four innings. In two appearances as a starter for the Crew, Thornburg surrendered seven runs across 10 innings.

The righty abruptly left his last relief outing, on Thursday, with a tired arm after appearing in back-to-back games for the first time this season. Seen as a future starter by the organization, Thornburg can benefit most from a return to that role, Roenicke said, so that the Brewers can get a better look at him later in the season. Thornburg, who said he has thrown every day since Thursday without any issues, had no arguments with the decision.

"It's always difficult to leave here," Thornburg said. "But I haven't been able to get some innings in, and in order to be a starter, I've got to go back down and work my pitch count back up and hopefully be back soon."

Aoki adjusting to MLB's trade culture

MILWAUKEE -- As a veteran of professional baseball in Japan, Brewers outfielder Norichika Aoki has had many new experiences during his first season in the United States. The latest came on Friday, when Aoki saw teammate Zack Greinke get traded away to the Angels.

In Major League Baseball, in-season trades involving star players are common and happen every season. That's not so in Japan, where Aoki said teams tend to hold onto their best players for longer.

"It is very interesting," Aoki said. "It's just a different way of seeing how things work. There are cultural differences, and that leads to different things. Over here, you trade someone who's going to be a free agent. In Japan, it might be like, 'Why are you trading him away?' There's still kind of a negative aspect to trading. In America, it's more of teams want you; that's why they take you. In Japan -- it's not so much anymore, but it's still there -- teams don't want you, and that's why you're getting traded."

Aoki named a number of factors that make trades such as the one between the Brewers and Angels uncommon in his home country. Players can't test free agency until after their eighth year in Nippon Professional Baseball, which is Japan's major league consisting of just 12 teams -- another reason Aoki said trades aren't as frequent. Also, as opposed to the deep farm systems of Major League clubs, organizations in Japan have just one Minor League team, limiting the number of prospects who can be dealt.

As a whole, Aoki, who didn't hesitate to ask questions when discussing the differences in the way front offices work in the two countries, said he prefers MLB's way of doing things. But that doesn't mean he's used to it.

"Right now, it feels weird that players are getting traded from our clubhouse, and I'm not going to see them every day anymore," Aoki said.

Although it's new for him, Aoki handled questions regarding the team's attitude following the Greinke trade like someone who's gone through it before, saying the Brewers "have to stay positive and just go out there every day and give it our best."

After being presented with the idea that his name could one day come up in trade rumors, Aoki, who was batting .280 with 21 RBIs entering Sunday, said that's not something he's interested in.

"I still have the thinking I had in Japan," Aoki said. "And for me currently, I just want to be able to play for the Brewers and succeed with the Brewers. But that thinking could change as I gain more experience and just get used to the system over here."

Nagging left wrist soreness sidelines Aramis

MILWAUKEE -- Brewers third baseman Aramis Ramirez sat out Sunday's series finale against the Nationals with a sore left wrist that has bothered him "for a while" but has not seemed to affect his doubles stroke.

Ramirez hit his 35th double in Saturday's 4-1 loss, inching closer to the Brewers' single-season record of 53 doubles set by Lyle Overbay in 2004. Ramirez is currently on pace for 57 doubles and is batting .286 with 12 home runs and 61 RBIs in his first season with Milwaukee.

"I'm fine," Ramirez said on Sunday. "I could use a day, but I've been playing with it for a while now. We agreed the first day of the series that [manager Ron Roenicke] was going to give me Sunday. It's been going on for a while, but I'm good enough to go out there and play. I'm sure there's a lot of guys in here who are not 100 percent, and I'm no exception."

Ramirez says the issue does not bother him on every swing but flares up from time to time. He also dismissed the notion that the injury has sapped his previously clockwork power.

In each of his last four full seasons -- he was limited in 2009 by a right shoulder injury -- Ramirez has hit 17 or 18 home runs through his first 93 games and finished with 25-27 homers. This season, Ramirez has 12 home runs through his first 93 games, even though he played early-season home affairs at climate-controlled Miller Park instead of windy Wrigley Field.

"We need to keep this guy healthy and swinging well," Roenicke said. "He's driving the ball to all parts of the park. He's wearing out the right-center-field wall. He's hit that I don't know how many times. The extra-base hits are really important, whether they're homers or whether they're doubles. I think they're really important for a third, fourth hitter. You come up with guys on base and those score everybody."

Last call

Roenicke hoped Marcum was back on track Sunday in his recovery from a mysterious right elbow issue. Marcum, out since mid-June with what has only been called "tightness" in his elbow, threw another bullpen session on Sunday morning, two days after he was unable to get loose in a similar session. With his move to the 60-day DL, Marcum is now eligible to return to active duty beginning Aug. 14.