In his first public comments since baseball’s winter meetings, Washington Nationals Manager Dave Martinez laid out his clearest vision yet of how he hopes to use the roster this season. The plan centers on Carter Kieboom, the organization’s top prospect, filling the hole at third base, and it includes the seemingly probable return of Ryan Zimmerman and potential lineup shuffling to compensate for the absence of Anthony Rendon.

The vote of confidence for Kieboom was Martinez’s most striking statement Friday afternoon when he met with reporters at the SiriusXM studios in Northeast Washington.

“We need to fill a void at third base, and we think he’s appropriate,” Martinez said of the 22-year-old. “He can do the job.”

When asked about the sign-stealing scandal that has rocked baseball and cost three managers their jobs this week, Martinez joked he heard about it because “they do have Google in Bali,” the Indonesian island where he and his girlfriend have been vacationing. But the manager followed Major League Baseball’s request for teams to not comment on the discipline levied against the Houston Astros. He did seem troubled, though, by what these managerial openings might mean for his coaching staff. Bench coach Tim Bogar was once a candidate for the New York Mets job that recently reopened after the team parted ways with Carlos Beltrán.

“It’d be tough to let guys go,” Martinez said. “We have our coaching staff set, and [other organizations will] have to get permission [to interview the coaches] this close in the game.”

The Nationals have plenty to sort out themselves. They will have three set infield positions if Kieboom pans out, but the rookie’s inexperience at third base makes that far from a given. Martinez wants to team shortstop Trea Turner with newly signed Starlin Castro as the “everyday” second baseman, because he said the team reviewed the 29-year-old’s defensive numbers and concluded second was by far his best position. The Nationals plan to platoon first base with ­left-handed hitter Eric Thames and a yet-unsigned right-handed hitter. Ryan Zimmerman fits the bill, and Martinez said the franchise remains in talks with the 35-year-old.

“I do believe it'll happen,” Martinez said of a reunion.

The key to the infield is Kieboom. The Nationals lost out on the Josh Donaldson sweepstakes Tuesday when he joined the Minnesota Twins, so the only other way the team could upgrade the position is via trade, which seems unlikely at this point.

Martinez believes Kieboom will hit, so he wants the rookie to focus primarily on defense at spring training. His development into even an average everyday player would prevent stretching the roster thin as the manager had to do during the team’s rocky start last season, and it would maximize roster flexibility. Martinez was asked whether he worried about replacing Rendon, an MVP candidate, with a rookie who made four errors in 10 games there for Class AAA Fresno last season.

“No,” the manager said, and he waved away concerns by citing Kieboom’s recent weight gain (15 to 20 pounds “of muscle”) and his instructions for Bogar to work with Kieboom at third early every day.

“The biggest thing about [Kieboom at third] is positioning,” Martinez added. “And I think once he learns how to play that position, and where to position himself, I think he's going to be okay.”

Kieboom, a natural shortstop, didn’t spend much time at third last season because the team focused his training on second base. That position, at the time, seemed a likelier avenue for him to the majors because the organization remained deep in talks with Rendon for a long-term extension. Then the third baseman had a monster postseason and earned a seven-year, $245 million contract with the Los Angeles Angels. The quick recalibration meant another reroute for Kieboom, a dizzying process Martinez wants to avoid this season so the team can “let him get used to playing third . . . and see what we got.”

“I want him to focus on just one position,” Martinez said. “If he’s going to be on our team, he’s going to play third base.”

If Kieboom doesn’t work out, or if the adjustment is slower than anticipated, Martinez said “we’ll cross that bridge when we get there.” He intimated the Nationals’ contingency plan is a platoon of veterans. There would probably be a heavy dose of Asdrúbal Cabrera and some Howie Kendrick.

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