The Nationals passed on making any selections in Thursday’s Rule 5 draft at the winter meetings at the Opryland Hotel in Nasvhille, instead losing four of their players to opposing teams. The Colorado Rockies drafted left-handed pitcher Danny Rosenbaum with the third pick and the Boston Red Sox took infielder Jeff Kobernus with the seventh selection of the major league portion of the draft, and then traded him to the Detroit Tigers.

“You obviously never want to lose any players,” Nationals assistant general manager Bryan Minniti said. “You set your rosters, you know you’re always taking chances on losing any of your prospects. It’s never good to lose a left-handed starting pitching prospect and a middle infield prospect. You wish them well, you wish them luck. At the end of the day, you hope you get them back at some point in the next year and don’t lose a hole.”

The Nationals receive $50,000 from each team for each major league transaction. The Rockies and Tigers will have to keep Rosenbaum and Kobernus on their 25-man roster all season or return them to the Nationals. 

The Nationals left Rosenbaum and Kobernus unprotected at the deadline to add players to the 40-man roster two weeks ago, opting instead to protect right-handers Erik Davis and Nathan Karns. This year, unlike seasons past, the Nationals had no need to select anyone in the Rule 5 draft given their filled major league roster — and instead had their own players targeted by opposing teams.

Losing Rosenbaum, in particular, further thins the Nationals starting rotation depth in the minor leagues — a position they have used to acquire Gio Gonzalez and Denard Span in trades. The Nationals still hope to add, through free agency or trade, starting pitchers they can stash in the minor leagues for depth.

“The challenging thing with the major league rotation we have is recruiting guys who know they’re probably going to end up in AAA, barring an injury,” Minniti said. “I don’t know if we’ll sign those guys any time soon, but we’ve had negotiations and conversations with guys for the last two months or six weeks. We’ll continue to try to sign guys to be depth for us. They’re critical guys.”

Rosenbaum, 25, spent all of last season in Class AA Harrisburg and, after a strong start, finished with a 3.94 ERA over 155 1/3 innings. The sinker-balling left-hander has been consistent over the past four seasons since the Nationals drafted him in the 22nd round in 2009.

Kobernus, 24, selected out of California-Berkeley by the Nationals in the second round of the 2009 draft, was one of the fastest players in the Nationals minor league system. He stole 42 bases last season in Harrisburg while hitting .282/.325/.333 while playing second base. Over the past two seasons, between Harrisburg and Class A Potomac, Kobernus stole 95 bases while being caught only 19 times.

In the minor league portion of the draft, the Boston Red Sox selected left-handed pitcher Jack McGeary and the Los Angeles Dodgers took right-handed pitcher Hector Nelo. The Dodgers probably benefited from the knowledge of Pat Corrales, the former Nationals front office special adviser who roved the minor leagues who was hired last month by Los Angeles.

McGeary, 23, who pitched in the minors and earned his Stanford degree at the same time after being drafted by the Nationals in the sixth round of the 2007 draft, tossed only 9 1/3 innings between the Nationals’ Gulf Coast League team and rookie ball Auburn. The left-hander, a Tommy John surgery survivor, hasn’t advanced higher than Class A Hagerstown.

Nelo, 26, was originally drafted by the Texas Rangers in the 15th round of the 2007 draft and joined the Nationals in 2011. The big-armed right-handed reliever posted a 2.73 ERA with Harrisburg last season in 52 2/3 innings and 16 saves. He had a 10.8 strikeout rate but struggled with command, a 5.0 walk ratio.