(J Pat Carter/AP)

According to a person with knowledge of the situation, the Nationals’ best offer to Buehrle was $39 million over three years – $19 million less than the Marlins paid in overall guaranteed money and $1.5 million less in average annual value. Buehrle felt Washington was a good fit for him and his family, but the Marlins convinced him to head instead to a divisional rival.

“I appreciate everything [Mike Rizzo] and the Nationals had to offer,” Buehrle said during an interview on MLB Network. “It just came down to comfort level.”

The Nationals made Buehrle their top free agent target this winter, even visiting him at his home in St. Louis to make their pitch. But Rizzo said he did not feel comfortable extending a fourth year to Buehrle, a 32-year-old with spotless injury history.

“That was an issue from the start,” Rizzo said. “We tried to work through that. But once he became comfortable with the fit in Miami, the term was right for him.”

With Buehrle in Miami, the Nationals will move on to “Plan B,” Rizzo said. The Nationals will pursue right-handed free agent Roy Oswalt. They have kicked the tires on a trade with the Oakland A’s for Gio Gonzalez, but after the A’s traded starter Trevor Cahill to the Diamondbacks, they seem likely to hold on to Gonzalez.

The Nationals could also enter the bidding for Yu Darvish, who was posted Thursday by his Japanese team, the Nippon Ham Fighters. The Nationals have until Wednesday at 5 p.m. to enter a bid to Nippon to win the right to negotiate with Darvish, a 25-year-old superstar who last season compiled a 1.44 ERA and led Japan’s highest professional league with 276 strikeouts.