Nate McLouth is a solid fourth outfielder, but the Nationals may still need to tweak other parts of their bench. (Jason Miller/Getty Images)

Like most MLB teams, the Nationals have been quiet since the new year began, hunting for non-roster invitees and preparing for arbitration cases. Their winter work is mostly done, and it has been mostly done since they traded for Doug Fister and Jerry Blevins and signed Nate McLouth.

But they are not quite finished tweaking, or at least trying to tweak, their roster. With their agreement with Jamey Carroll last week, the Nationals added another player likely to make their opening day bench. But that bench may not be settled quite yet.

As presently constituted, the Nationals’ bench can fill many roles. In McLouth, the Nationals have a speedy, solid defensive outfielder who has a little power and is capable of filling in for long stretches. In Carroll, the Nationals have a veteran who will help in the clubhouse and has an excellent track record as a pinch hitter. Danny Espinosa is an elite defensive infielder. Scott Hairston shows power against left-handed pitchers. The Nationals like the potential of both Jhonatan Solano and Sandy Leon. When he’s right, Tyler Moore hits for power and can hit both lefties and righties.

But the bench, as presently constituted, also presents some questions. McLouth is a very solid fourth outfielder; on some teams, he would start. Other than that, the Nationals could stand to shore up other areas.

Do they need another catcher? Wilson Ramos is entrenched as the starter, and Solano, Leon and Chris Snyder will vie to be his backup. Given Ramos’s injury history, it may be risky to enter the season without another option. Solano (who is probably the favorite) and Leon are inexperienced, and Snyder has struggled offensively through back injuries the past two seasons.

John Buck is probably the best free agent catch still available, but the Nationals are not high on him, or at least they weren’t earlier this winter. Michael McKenry and Yorvit Torrealba are also available. Both have a better recent track record than Sndyer, but neither would seem to be a significant upgrade.

Do they need another left-handed hitter? McLouth on most night will be the Nationals’ top left-handed pinch hitter. McLouth did hit 12 homers and 31 doubles last year, but the Nationals do not have much power from the left side off the bench. Espinosa could fill that void if he bounces back, but that is a reasonably big “if.” Mike Fontenot, signed last week to a minor league deal, could be another lefty bat, but he’s never hit with much power. On some nights, Adam LaRoche may be that bat – the Nationals have toyed with giving Ryan Zimmerman some starts at first against tough left-handed starters.

The best fit remaining in the free agent pool would probably be Lyle Overbay, who hit 14 homers for the Yankees last year in limited playing time.

Do they need more power off the bench? Both Tyler Moore and Hairston pose threats, but both also had down seasons in 2013. Moore shuttled between Syracuse and the majors, and Hairston hit .191. Moore seeks consistency, but he would need to cut down on strikeouts to achieve it. The Nationals may have a sleeper in non-roster invitee Brock Peterson, who hit 25 homers and slugged .531 for Class AAA Memphis last year.

Mark Reynolds, who has both cartoonish power and cartoonish strikeout totals, still seeks a team. He was a Mike Rizzo draft choice in Arizona in 2004. He was also Ryan Zimmerman’s college teammate. The Nationals also showed interest earlier in the winter in Jeff Baker, a Scott Boras client who can play all four corners and demolished left-handed pitching last season. Baker remains a free agent.

As for the bullpen, the Nationals probably made their last significant move when they added Blevins. If they go with a second left-handed reliever, it would likely be Xavier Cedeno, who was excellent in limited chances last year. He had a 1.31 at Class AAA Syracuse. In 31 major league plate appearances against lefties, Cedeno struck out eight and allowed one extra-base hit.

Oliver Perez and Ryan O’Flaherty, both targets earlier this winter, remain free agents. So does former National Michael Gonzalez, who could likely be had with a minor league deal. But Rizzo seems content with their current makeup.

“We feel comfortable with where we’re at in the ‘pen,” Rizzo said last week. “We feel that [Cedeno is] a guy that can get left-handed hitters out. He also has [minor league] options left. He’s going to go to spring training and compete for a spot.”