Edwin Jackson is pitching for a spot in the Nationals’ rotation. (Douglas DeFelice/USA TODAY Sports)

When you pitch for 12 organizations across a decade-and-a-half, like Edwin Jackson, you figure out how the professional baseball world operates. In his 15-year path from teenage super-prospect to respected veteran, Jackson learned the business is unforgiving and only grows colder with age. So he just seeks honesty in business dealings. No backtracking. No sugarcoating. He thinks he found that in the Nationals’ front office, which factored into his decision to re-sign with Washington over the winter.

“They’re going to keep it straight with you,” Jackson said recently at his locker in West Palm Beach, Fla. “That’s the biggest thing you can ask for: an organization to keep it real with you and let you know where you stand.”

This is where the 34-year-old Jackson stands on March 13: in competition for the final spot in the Nationals’ rotation with A.J. Cole and Erick Fedde, though that is subject to change should the team acquire a starting pitcher. If it doesn’t, however, club officials have repeated that Cole, who doesn’t have a minor league option remaining, is the front-runner for the vacancy, meaning Jackson will likely start the season with Class AAA Syracuse. Jackson would have to accept the assignment because he can’t opt out of his minor league contract until June 1.

“It’s not necessarily the ideal situation for me,” Jackson said on Tuesday after his third start of the spring. “But if that’s what happens, I guess I have to deal with that when it comes.”

Last offseason, Jackson waited and waited for an offer he deemed acceptable. The strategy backfired. He spent spring training on his own in Arizona, throwing bullpen sessions instead of competing for a spot on a major league roster. He went unsigned until accepting a minor league offer from the Orioles after Opening Day. He pitched for Baltimore’s AAA affiliate and appeared in two games for the Orioles before he was designated for assignment.

He then signed a minor league deal with the Nationals in June, five years removed from helping Washington reach the postseason for the first time in club history, and posted a 0.44 ERA in five outings before getting another call to the majors.

Jackson’s second stint in Washington was a tale of two extremes. In his first eight starts, he pitched to a 2.94 ERA. In the next four, he compiled a 12.38 ERA. He allowed two runs across six innings in his final outing. He attributed the swoon to his delayed start.

“I had a little downfall where it would normally be right before the all-star break,” Jackson said. “It happened to be at the end of the season just because I had the late start. It was unfortunate, but for the most part I came in and helped the team when we needed it most — when it was down starters and needed innings to get to September, to the end.”

Jackson returned to the Nationals even as speculation that they’d potentially sign a free agent pitcher to fill that open rotation slot swirled. Those chances took a hit over the past week with Lance Lynn and Jake Arrieta finally moving off the market. Other options, including Alex Cobb, remain, but the Nationals are more likely to begin the season with their current options than a week ago.

“He gets it,” Nationals Manager Dave Martinez said of Jackson. “He knows he has to try to make the team. But he’s done well.”

Jackson has made his case by pitching to a 3.00 ERA in three spring outings. On Tuesday, he made the three-hour trip to Lakeland — another sign of where he stands in the pecking order — and surrendered one run on three hits and two walks over three innings against the Tigers. His stuff — and that fastball in the mid-90s — is still there. The focus, as always, has been on avoiding command lapses, which kept Jackson from reaching his potential and sticking with one franchise for long.

“Right now my biggest thing is make ’em put the ball in play,” Jackson said. “Coming into today, outside today’s game, walks have been down. I’ve been making people put the ball in play. That’s my biggest thing. If I can be aggressive around the strike zone and stay in pitcher’s counts and stay aggressive around the plate to let the defense work, I’ll take my chances.”

Most players maintain spring training competition doesn’t change matters, but Jackson admitted competing for a spot is “different.” Results this early could matter. Familiarity helps. While his teammates, for the most part, have spent the past few weeks getting acquainted with their overhauled coaching staff, most of the faces weren’t new to Jackson. He worked with Martinez and first base coach Tim Bogar in 2008 when they were with the Rays, and with pitching coach Derek Lilliquist in 2011 when they were with the Cardinals. It’s another perk of Jackson’s travels. He’s sure there’s more to his journey.

“I’m 34 and I’ve been around a while,” Jackson said. “I still got something in the tank, though, man. I still got a lot in the tank, I feel like. I’ll continue to grind until the end.”

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