Washington obtained right-hander Doug Fister from Detroit for infielder Steve Lombardozzi and left-handers Robbie Ray and Ian Krol on Monday. Oakland acquired closer Jim Johnson from Baltimore for infielder Jemile Weeks and a player to be named.
Fister was 14-9 with a 3.67 ERA last season for the AL Central champions, who last month traded slugging first baseman Prince Fielder to Texas for second baseman Ian Kinsler.
"It gives us some flexibility for some other things we want to do," Tigers general manager Dave Dombrowski said, insisting the trade wasn't made to free money for a long-term deal for AL Cy Young Award winner Max Scherzer, who can leave after next season.
Fister joins a talented Nationals rotation that already includes Stephen Strasburg, Jordan Zimmermann and Gio Gonzalez.
Oakland, which also closed in on a $22 million, two-year contract with left-hander Scott Kazmir, is revamping after losing to the Tigers in the AL division series.
The 30-year-old Johnson led the majors with 51 saves in 2012 and tied for the big league lead last season with 50. The two-time AL West champion A's found their closer to replace All-Star Grant Balfour, who became a free agent after the season and is expected to command a multiyear deal.
Meanwhile, 43 players became free agents at midnight EST when their teams failed to offer 2014 contracts, a group that included 2009 NL Rookie of the Year Chris Coghlan (Miami) and St. Louis reliever John Axford.
Clubs often use the so-called tender deadline as leverage to force agreements with players they won't go to arbitration with. Among the players let loose were Toronto catcher J.P. Arencibia, Boston right-hander Andrew Bailey and outfielder Ryan Kalish, Mets right-hander Jeremy Hefner, Yankees infielder Jayson Nix, Tampa Bay outfielder Sam Fuld and Kansas City infielder Chris Getz.
The Los Angeles Angels gained nearly $10 million of payroll flexibility, declining to offer contracts to pitchers Tommy Hanson, Jerome Williams and Juan Gutierrez along with third baseman Chris Nelson.
With an excess of catching after reaching an agreement to sign Brian McCann, the New York Yankees traded Chris Stewart to Pittsburgh for a player to be named, and Stewart agreed to a $1 million, one-year deal with the Pirates. The Yankees also finalized a $5 million, two-year contract with shortstop Brendan Ryan, who became their starter in September when Derek Jeter went back on the disabled list.
Kazmir's deal with Oakland is pending a physical, a person said, speaking of anonymity because the team hadn't finalized the contract. The 29-year-old left-hander went 10-9 with a 4.04 ERA in 29 starts and 158 innings last season for Cleveland and becomes part of a rotation that includes Sonny Gray and A.J. Griffin. The Athletics probably won't pursue a new deal for 40-year-old Bartolo Colon, an 18-game winner.
Utilityman Willie Bloomquist agreed to return to Seattle pending a physical expected to take place later this week, a baseball official with knowledge of the deal said, also speaking on condition of anonymity because the agreement wasn't final. Bloomquist spent his first seven big league seasons with Seattle and the past three with Arizona. He hit .317 for the Diamondbacks this year but had just 139 at-bats.
Catcher Dioner Navarro agreed to an $8 million, two-year contract with Toronto that pays $3 million next year and $5 million in 2015. The 29-year-old batted .300 with a career-high 13 homers and 34 RBIs in 89 games for the Chicago Cubs last season. An All-Star in 2008, he has not played more than 89 games in a season since 2009 because of injuries.
Another catcher, Jose Molina, agreed to a $4.5 million, two-year contract to remain with the Tampa Bay Rays.
Thirteen players eligible for arbitration agreed to one-year deals: San Diego left-hander Eric Stults ($2.75 million) and right-hander Tim Stauffer ($1.6 million); Baltimore outfielders Nolan Reimould ($1,025,000) and Steve Pearce ($850,000); Atlanta left-hander Jonny Venters ($1,625,000) and infielder Ramiro Pena ($700,000); Washington right-hander Ross Ohlendorf ($1.25 million); Detroit outfielder Don Kelly ($1 million); Chicago White Sox catcher Tyler Flowers ($950,000); Philadelphia first baseman Kevin Frandsen ($900,000); Oakland right-hander Fernando Rodriguez ($600,000); and Cleveland right-handers Frank Herrmann and Blake Wood ($560,000 each);
In agreements announced Friday, the Los Angeles Dodgers reached deals with outfielder Mike Baxter and catcher Drew Butera ($700,000 each) and left-hander Scott Elbert ($575,000).
AP Baseball Writer Janie McCauley and AP Sports Writers Tim Booth and Larry Lage contributed to this report.