Oakland received minor league reliever David Shafer in the deal. Each team also received a player to be named.
Saarloos, 27, went 7-7 with two saves and a 4.75 ERA last season for the American League West champions. After being Oakland's No. 5 starter in 2005, he made 16 starts and 19 relief appearances last year.
The Reds are trying to fill out their rotation and bolster a bullpen that was one of their major problems last season. Saarloos could fit in either place.
"That will be something that gets decided in spring training," Reds general manager Wayne Krivsky said.
The Reds also agreed to a minor league contract with infielder Mark Bellhorn and invited him to spring training. Bellhorn, 32, spent last season with San Diego, hitting .190 in 115 games.
Blue Jays -- Right-hander Tomo Ohka and Toronto reached a preliminary agreement on a one-year contract. Blue Jays general manager J.P. Ricciardi said the deal was pending a physical.
White Sox -- Outfielder Scott Podsednik, a hero in the 2005 World Series who slumped last season, will be sidelined six weeks after having groin surgery, according to several reports. The White Sox are also close to signing free-agent outfielder-first baseman Darin Erstad, the Chicago Tribune reported on its Web site.
Red Sox -- Boston avoided arbitration with right-hander Brendan Donnelly by agreeing to a one-year, $1.4 million contract. The deal also calls for bonuses of $25,000 each if he finishes 25 games and 30 games.
Mets -- First baseman Carlos Delgado could miss a few games at the start of the regular season for the birth of his child.
Angels -- Los Angeles infielder Dallas McPherson underwent surgery to remove a herniated disc in his lower back and is expected to be sidelined for most, if not all, of 2007.
2008 All-Star Game -- Baseball is set to announce Yankee Stadium as site of the game. Commissioner Bud Selig will hold a news conference at New York's City Hall with Mayor Michael Bloomberg next Wednesday.