Keith Frandsen (AP Photo/Kathy Willens)

The Nationals added the final piece to their opening day bench this morning when they signed veteran infielder Kevin Frandsen to a one-year contract guaranteed to pay at least $900,000 and worth up $1.2 million with bonuses, according to a person familiar with the situation.

All spring, the Nationals seemed to be choosing between veteran infielder Jamey Carroll and slugging first baseman/outfielder Tyler Moore. Once Frandsen opted out of his contract with the Phillies on Tuesday, he presented the Nationals a sort of hybrid. Like Carroll, he can play second and third base and has experience batting off the bench — he led the majors with 14 pinch hits last season. Like Moore, and unlike anyone currently on the Nationals’ bench, Frandsen can play first base.

Frandsen, 31, opted out of his deal after the Phillies sent him to Class AAA. Later that afternoon, the Nationals optioned Moore to Class AAA Syracuse and released Carroll.

Manager Matt Williams declined to discuss Frandsen directly, because the Nationals need make other moves, including removing a player from their 40-man roster, before making the signing official. But in general, he said he would value versatility in any addition.

“I like options,” Williams said. “Options are good. If in fact we were to look for somebody else, it would be somebody that would give us multiple options, that has the ability to play multiple positions. That’s important for your team to have guys that can move around, that are experienced in that regard.”

Frandsen, a right-handed hitter, batted .280/.333/.389 with seven home runs over the past two seasons with the Phillies. In 88 plate appearances against left-handed pitchers last year, Frandsen hit .311/.409/.459.

Utility man Jeff Kobernus and catcher Sandy Leon remain in camp. Outfielder Scott Hairston, who has a $2.5 million guaranteed salary, will presumably make the  roster, although Williams has yet to explicitly confirm his place on the team.

UPDATE, 12:37: The Nationals cleared room for Frandsen on their 40-man roster by placing right-hander Ross Ohlendorf on the 60-day disabled list with a right lumbar strain. Ohlendorf, who will make $1.25 million guaranteed this year, had been optioned earlier this week.