Marrero, who is considered a backup first baseman, hurt the hamstring stretching for a thrown ball. One baseball source said he could be out for the season because the hamstring was torn off the bone. But Marrero denied that he would miss the entire season.
"I'm not out for the season, but I did tear my hamstring." Marrero said via telephone. " ... I didn't think it was that bad, but once I went to the doctor in DC, he said it was torn and I had surgery. But I'm not going to miss the season. I'll miss some time in Spring Training to make sure that it's 100 percent. I don't know what the doctor has planned, but I know I'm not going to miss the season."
Marrero, a first-round pick in the 2006 First-Year Player Draft, made his Major League debut this past season, hitting .248 with 10 RBIs and playing solid defense at first base.
With Marrero not expected to be ready by the time Spring Training begins, the Nationals are looking to acquire bench strength at first base. According to one source, the Nationals are looking at free agent Mark DeRosa, who can play several infield positions, including first base. DeRosa can also play the corner outfield spots.
DeRosa played for the Giants this past season, hitting .279 with 12 RBIs in 47 games. Calls to general manager Mike Rizzo were not returned. Rizzo is expected to address issues on the bench starting Monday when the Winter Meetings begin in Dallas.
Meanwhile, according to a report from Foxsports.com, the Nationals have expressed interest in Prince Fielder. One baseball source questioned the report due to the presence of first baseman in Adam LaRoche, who will make $8 million this year. The source indicated that the Nationals have other pressing needs, like finding a center fielder and leadoff hitter. The club is also looking for a starting pitcher to help lead a starting staff that includes Stephen Strasburg and Jordan Zimmermann.
At the same time, LaRoche, who missed most of the 2011 season because of shoulder problems, told MLB.com in late October that he wasn't promised the starting job at first base next season.
"Obviously, anything can happen. That's their decision," LaRoche said. "That's a pretty big investment for someone who is not playing. I don't know what direction they would go. Obviously, anything is possible."
Bill Ladson is a reporter for MLB.com and writes an MLBlog, All Nats All the time. He also can be found on Twitter @WashingNats. This story was not subject to the approval of Major League Baseball or its clubs.