Span trade probably puts Harper in left

With the addition of Denard Span, the Washington Nationals aren't just plugging a player into the lineup and moving on. He's like a new piece of furniture that causes an entire room to be redecorated, just so everything is in the perfect spot.

The Nationals acquired the center fielder from the Minnesota Twins for minor league pitcher Alex Meyer on Thursday, setting off a chain reaction for the National League East champions.

With Span in center, 20-year-old Bryce Harper moves to a corner spot - probably left field, with Jayson Werth staying in right. Michael Morse could then move to first base - the position played by free-agent slugger Adam LaRoche.

Also, with Span hitting leadoff, Werth drops a few spots in the batting order. And with either Morse or LaRoche seemingly on the way out, Harper, the former Las Vegas High School and College of Southern Nevada standout, could move down in the lineup as well.

Span batted .284 with 90 steals and a .357 on-base percentage over five seasons with the Twins. He is the type of player the Nationals have been seeking since moving to Washington in 2005.

"He's going to bring a dimension to the club that we haven't had before," general manager Mike Rizzo said, "a fast-moving, exciting guy that makes contact and moves the guy around and can fly around the field."

Harper is also fast-moving and can fly around the field - although he hits with much more power than Span and is a converted catcher. Harper had some adventures in center field this season but was also a sparkplug, doing enough with his bat and glove to win the NL's Rookie of the Year award.

Nevertheless, the Nationals have always wanted to move him one spot over.

"(Harper) is a terrific young center fielder," Rizzo said. "But we felt for his long-term development and his career path that we wanted to move him out of a taxing position of center field, both mentally taxing and physically taxing. We've accomplished that."

Span is entering the fourth year of a $16.5 million, five-year contract with a $9 million club option for a sixth year.

■ YANKEES - Mariano Rivera and New York agreed to a $10 million, one-year contract, a person familiar with the negotiations said. The person said the deal includes additional bonus opportunities.

After missing most of last season because of a knee injury, Rivera accepted a cut in guaranteed money from his previous $30 million, two-year deal.

■ PIRATES - Pittsburgh agreed to a $17 million, two-year contract with three-time All-Star catcher Russell Martin, hoping he can give them some pop at the plate and respectable defense.

Martin, 29, hit .211 with 21 homers and 53 RBIs in 133 games last season with the Yankees.