Source: Nats sign infielder Castro to two-year deal

The Nationals added another piece to their ever-changing infield puzzle this afternoon, signing the versatile Starlin Castro to a two-year, $12 million contract that doesn't prevent them from continuing to pursue star third baseman Josh Donaldson.

The deal, which is pending a physical, was confirmed by a source familiar with the terms after first being reported by The Athletic.

Castro, 29, is a four-time All-Star who first made a name for himself as the Cubs' potential long-term shortstop, but he's bounced around since, spending two seasons with the Yankees and then two more with the Marlins. Along the way, he shifted primarily to second base, though he also played 45 games at third base last season in Miami.

The Nationals, according to the source, view Castro mostly as a second baseman at this point while still valuing his ability to play both third base and shortstop if needed. Essentially, he takes over the role held last season by Brian Dozier, now an unsigned free agent.

Because of that, the club intends to continue its pursuit of Donaldson, hoping to win out a bidding war over the Braves, Twins and Dodgers. If Donaldson heads elsewhere, they could still pursue another natural third baseman to replace departed All-Star Anthony Rendon.

Castro is a career .280 hitter with a .319 on-base percentage and .733 OPS in 10 big league seasons. He hit a career-high 22 homers with 86 RBIs last year for the Marlins, though he remains a free swinger who strikes out a lot and doesn't draw many walks.

If nothing else, Castro has proven durable over the years. He played in all 162 games last season and has averaged 149 games played over the last nine seasons.