In 11 years playing in the Major Leagues, Raburn has hit .253/.317/.436 with 91 home runs. The 6-foot, 185-pound outfielder played 113 games with the Rockies last season, batting .220 with nine home runs and 30 RBIs.
It originally seemed that Raburn would serve as a replacement for Chris Heisey, who ruptured his biceps tendon Tuesday, but Heisey said he's been cleared for baseball activities. Still, the Nationals could use a pure right-handed reserve hitter if they call Raburn up.
On Wednesday, the Nationals placed Heisey on the 10-day disabled list. His MRI exam on Thursday confirmed the injury.
Heisey said there are two biceps tendons, and he ruptured the less important one. He threw the ball around during batting practice before the Nationals' game against the Padres on Friday night.
"In theory, I'll be about 10 percent weaker during biceps-related exercises, but for the most part that's not a baseball move," Heisey said. "We're not power lifting. You can obviously build that up, build the other part up. I don't do a whole lot of biceps curls anyway."
Heisey first felt severe pain after striking out against the Mariners on Tuesday night. The 6-foot-1, 220-pound outfielder received treatment prior to the Nationals' win over Seattle on Wednesday, but he grimaced and limped out of the cage after one batting-practice swing. The Nationals recalled outfielder Brian Goodwin as his replacement.
For the next 10 days, Heisey said he'll swing and throw around to see how he's feeling.
"For whatever reason I have really bad pain, then we'll re-evaluate," Heisey said. "But they don't anticipate I will."
In 47 at-bats this season, Heisey is hitting .128. After holding a .273 batting average on April 19, his hitting numbers have declined. He's taken the second most at-bats of Nationals bench players.
Kyle Melnick is a reporter for MLB.com based in Washington.