VIERA, Fla. -- The Nationals signed catcher Josh Bard to a Minor League contract with an invitation to Spring Training on Saturday. Bard will earn $600,000 if he makes the 25-man roster and is expected to start working out with the club on Sunday.

Bard, who was released by the Red Sox earlier this week, will compete with Wil Nieves and Javier Valentin for the backup role behind the plate. Bard was 6-for-14 (.429) in six exhibition games before his release.

"We are never going to stop improving our club, be it inch-by-inch or step-by-step. We think it's going to be a good competitive situation," assistant general manager Mike Rizzo said. "There are three guys fighting for the catching job. Like I told you before, the best 25 guys are going north. We have two weeks to figure out who is the best of the three."

Nieves was the team's backup catcher last year and ended up having the best season of his big league career, hitting .261 with a home run and 20 RBIs.

Asked if there were concerns about Nieves' bat, manager Manny Acta said, "There is no concern about anything. We are trying to get better and better. If you can find somebody that is going to be better for our club, then we are going to move into that direction."

Bard, 30, will be playing for his second National League team. He played for the Padres for more than two years and had a .282 average for them. Bard also brings postseason experience, having appeared in three games with San Diego during the 2006 National League Division Series.

Originally selected by the Rockies in the third round of the 1999 First-Year Player Draft out of Texas Tech University, Bard made his big league debut with Cleveland in 2002.