PORT CHARLOTTE, Fla. -- The Rays traded Jose Lobaton to the Nationals on Wednesday for right-handed pitching prospect Nathan Karns, making Lobaton the odd man out of the team's troika of Major League catchers.

Also sent to the Nats were left-hander Felipe Rivero and outfielder Drew Vettleson.

Prospect acquired by Rays

Nathan Karns, RHP: Karns was ranked No. 5 on the Nationals' Top 20 at the time of the trade. A 12th-round Draft pick in 2009 who signed for $225,000 with Washington, it took quite some time for Karns to get his professional career off the ground. The Texas Tech product tore his right labrum not long after signing and didn't throw a competitive pitch until 2011.

Karns appeared to put the injury behind him in 2012, leading the Minor Leagues in batting average against (.174) and striking out 11.5 batters per nine innings. He built on that in 2013 with a .224 BAA and 10.5 K/9, making his big-league debut at age 25.

Karns has always had the kind of power stuff to get hitters out, though he struggled with consistency and command in college, then had to get past the shoulder issue as a pro. His fastball will reach the mid-90s consistently and he throws it downhill, generating a good amount of ground-ball outs in the process. Karns' breaking ball -- a big power curve -- is a swing-and-miss pitch. And his changeup, while behind the other two, gives him a third usable weapon. He commands his fastball relatively well, though his overall command is still a bit inconsistent. If Karns can continue to show improvement in that area, as well as with his offspeed stuff, he has the chance to start -- something the Rays believe he can do.

Top 20 Prospects: Rays | Nationals
-- Jonathan Mayo

Karns, 26, spent the majority of the 2013 season with Double-A Harrisburg, going 10-6 with a 3.26 ERA and 155 strikeouts in 23 starts. He also made three starts with Washington, including his Major League debut on May 28 against Baltimore.

"We feel like he has a chance to be a really good Major-League starting pitcher," said Rays executive vice president of baseball operations Andrew Friedman. "He's a big, strong, physical guy. [He has a] plus fastball, plus breaking ball, and the changeup really came on for him last year. We think he's got the size, strength, durability to be a guy to potentially put 200-plus innings on his body."

Jeremy Hellickson recently underwent right elbow surgery to "clean up some loose bodies" and won't be back until May, which depleted the depth of the organization's starting pitching. Friedman allowed that concern about depth crept in as a small motivator for making the deal.

"Starting pitching depth can be fleeting," Friedman said. "…You get in a situation where you have a setback or two with other guys, it just gets a lot more uncomfortable."

However, a desire to land Karns proved to be Tampa Bay's biggest motivation to make the deal. They had a lot of interest from other teams in Lobaton, so they looked at many players.

"Eventually we got to a point where we were able to line up on something [with the Nats]," Friedman said.

Over three Minor League seasons, Karns is 24-12 with a 2.66 ERA in 60 games (54 starts). He has averaged 10.7 strikeouts per nine innings pitched and opponents have hit only .194 against him. Karns was named the Nationals' Minor League Pitcher of the Year in 2012, going 11-4 with an organizational-best 2.17 ERA and 148 strikeouts in 24 games (18 starts) between Class A Potomac and Class A Hagerstown.

A 12th-round selection in the 2009 First-Year Player Draft out of Texas Tech University, Karns did not pitch professionally until 2011 due to right shoulder surgery.

Lobaton, 29, became expendable when the Rays acquired Ryan Hanigan from the Reds. Hanigan is expected to get most of the action at catcher, with veteran Jose Molina serving as his backup.

While Lobaton only makes $900,000 and is under the team's control for the next three seasons, the fact that he is out of options made such a trade necessary. While a need might have arisen due to injury with another club or even the Rays, chances are Tampa Bay would have lost Lobaton at the end of Spring Training had the club tried to sneak him through waivers. The team's only other alternative would have been carrying three catchers. That would have been a difficult premise based on the club's ongoing pursuit of more offense.

According to Friedman, keeping all three catchers was a possibility.

"It was absolutely a real possibility," Friedman said. "In a perfect world, I wanted to avoid it."

Had Lobaton been in camp, Friedman felt he would have been a distraction given his situation.

Lobaton, remembered by Rays fans for his dramatic game-winning home run off Koji Uehara that landed in the Rays Tank in center field during Game 3 of the 2013 American League Division Series, has spent the last three seasons with Tampa Bay. He is a career .228 hitter with a .654 OPS, and he hit seven homers with 32 RBIs last year. Lobaton is expected to back up Wilson Ramos with Washington.

Rivero, 22, spent the 2013 season with Class A Charlotte and went 9-7 with a 3.40 ERA. He is 29-25 with a 3.45 ERA and 315 strikeouts over five career Minor League seasons.

Vettleson, 22, hit .274 with four home runs and 62 RBIs for Charlotte in 2013, leading the Stone Crabs in hits while ranking second in RBIs. The former first-round selection (42nd overall) in the 2010 First-Year Player Draft owns a career .276 batting average, 26 home runs and 171 RBIs over three Minor League seasons.

Rivero and Vettleson were not players the Rays wanted to part with.

"We like both guys," said Friedman, who said Tampa Bay had the organizational depth to trade the pair before adding: "Both of them still have a chance to be really good Major League players."