Jerry Blevins walks off the mound during the eighth inning of a spring training game. The Nationals traded Blevins to the Mets Monday for outfielder Matt den Dekker. (AP Photo/Carlos Osorio)

The Nationals traded left-handed reliever Jerry Blevins to the Mets on Monday in exchange for 27-year-old outfielder Matt den Dekker, plucking from a surplus of left-handed relievers to gain outfield depth that has become increasingly necessary as injuries have slowed projected starting outfielders and bench options.

As of Monday morning, Blevins, Xavier Cedeno, Rich Hill and veteran fire-baller Matt Thornton were the left-handed relievers still in Nationals camp. Manager Matt Williams said he would like to carry two of them. Thornton, 38 and making $3.5 million this season, appears a lock to remain. Blevins will make $2.4 million this year. He has been hit hard this spring, and gave up three runs in 1 2/3 innings over his past two outings. Both of those outings came against the Mets, a brief audition for the creative lefty, who gave up 31 runs in 57 1/3 innings last year and held left-handed batters to a .160 average.

“We like the relief depth that we have,” General Manager Mike Rizzo said. “Jerry had one year left on his deal. We traded from a place of depth for a place of need not only for this year. He’s a young guy with two options left. The skill set fits for us.”

The Mets, who acquired left-handed reliever Alex Torres from the Padres earlier in the day, sent the Nationals left-handed hitting outfielder den Dekker. Den Dekker was competing for New York’s fifth outfield spot with Kirk Nieuwenhuis. Den Dekker has minor league options remaining. Nieuwenhuis does not, and so den Dekker was unlikely to win that job out of camp.

Den Dekker appeared in 80 games for the Mets over the past two seasons and hit .238 with a .345 on-base percentage and .322 slugging mark. He hit .328 with six doubles over the final two months of the season, and is solid defensively.

His skill set is important to us,” Rizzo said. “He runs really well, he can play plus defense at all three spots, he gives us another defender that can play above-average center field, and we like his left-handed bat. We’ve seen him play a lot in the last couple of seasons, and think he’s a guy whose skill set fits for us, for this year and for beyond.”

The Mets drafted den Dekker in the fifth round of the 2010 draft. A University of Florida product, den Dekker played high school ball at Westminster Academy in Fort Lauderdale, Fla., where Nationals center fielder Michael A. Taylor played his prep ball. Den Dekker is hitting .256 in 22 spring training games. He enters the Nationals’ wide open bench competition, which fellow left-handed contact hitter Tony Gwynn Jr. has all but won with a standout spring. But with Nate McLouth’s return from August shoulder surgery slogging along, the Nationals are short on left-handed hitters and short on outfielders. They were not short on left-handed relievers, and so the deal addresses a need without creating another.

“The injured guys are making faster progress than we anticipated so that’s a good thing,” Manager Matt Williams said. “That’s a situation where he gives us a lot of different options, certainly. It was a guy that, once they wanted to look at a left-hander from us, we looked at all of our options certainly. And he fits the bill.”

Blevins’s departure likely creates a bullpen spot for 28-year-old Cedeno. Like Blevins, Cedeno is not overpowering, relying on a fastball that sits around 90 mph, a curveball and a change-up. He has pitched 13 major league innings for the Nationals over the past two seasons, yielding four runs and striking out 11. He pitched to a 2.29 ERA and a stellar .864 WHIP in 35 games with Class AAA Syracuse last season. In 39 1/3 innings, he struck out 57 batters.

But whatever Cedeno contributes to the new-look Nationals bullpen, Blevins’s departure will be felt in the Nationals clubhouse and among Washington fans, who grew fond of the eccentric left-hander for his personality on Twitter and well-documented cat sweater.

The Nationals made another move to bolster their outfield depth Monday, signing veteran Reed Johnson to a minor league deal with an invitation to what little remains of major league spring training. The Marlins released Johnson earlier in the day. The 38-year-old will be added to growing list of outfielders available to provide major league depth or minor league options, a list that includes Gwynn, Mike Carp, den Dekker, and even left-handed hitting Clint Robinson, who is a first baseman by upbringing but has played the outfield to create a spot for his powerful left-handed bat. Johnson hit .235 in 113 games for Miami last season, can play all over the outfield and has proven himself as a pinch hitter. His 16 pinch-hits last season were the second most in the majors.