Right-hander Dan Haren makes his Washington Nationals debut Friday when they visit Great American Ball Park to open a three-game series against another National League division champion from 2012, the Cincinnati Reds.
The Nationals won the NL's East Division and were knocked out of the playoffs in the opening round by the St. Louis Cardinals, while the Reds won the NL Central and were beaten in five games by the eventual world champion San Francisco Giants.
Haren, a 32-year-old Californian, made 30 starts in the American League with the Los Angeles Angels of Anaheim and was 12-13 with a 4.33 earned run average in 176 2/3 innings.
His return to the National League is his first since 2010, which he began with the Arizona Diamondbacks before being dealt to the Angels.
Haren signed a one-year deal with the Nationals in the offseason for $13 million.
He is 2-2 in six career meetings with the Reds.
Cincinnati counters with righty Homer Bailey, who comes off a career-high 13 wins in 2012, including a late-season no-hitter.
Bailey, the seventh draft pick in 2004, reached the majors in 2007 and won four games, but never exceeded nine wins in a season until last year, when he was 13-10 in 33 starts with a 3.68 ERA.
The no-hitter came in his second-to-last start of the season on Sept. 28 in Pittsburgh, a game in which he struck out 10 and walked one in a 1-0 Reds triumph.
Bailey is winless in two career meetings with the Nationals.
On Thursday in Washington, Jayson Werth hit a three-run homer and scored twice as the Nationals beat the Miami Marlins, 6-1, to complete a three-game sweep.
Ryan Zimmerman went 3-for-3 with two RBI for the Nationals, who had never swept their initial series of a season. Bryce Harper went 2-for-4 with an RBI and a run scored.
Jordan Zimmermann (1-0) gave up one run on eight hits over six innings to pick up the win. The right-hander went 12-8 with a 2.94 ERA in 32 games last season.
Henry Rodriguez, Tyler Clippard and Craig Stammen each tossed a scoreless inning of relief to secure the victory.
In Cincinnati, Chris Heisey hit a two-run homer to help the Reds beat the Los Angeles Angels of Anaheim, 5-4, in the rubber match of baseball's first season-opening interleague series.
Heisey is hoping to make the most of his opportunity as the Reds' everyday left fielder following the injury to Ryan Ludwick. His blast was one of three given up by offseason addition Joe Blanton, who worked five innings in his Angels debut.
Bronson Arroyo (1-0) got the starting nod in the 20,000th game in Reds history and departed after six frames with his team up 5-3.
Washington won five of seven games against the Reds in 2012, including two of three in Cincinnati.