He began his professional career in Princeton in the Appalachian League and did relatively well. The next season, he advanced to A-ball but missed half the season due to an injury. He repeated the level the following season and was able to get his career back on track.
Johnson made slow, but steady progress through the lower rungs of the Rays system. He opened 2005 in the California League where he went on a power binge. Promoted to Double-A Montgomery midway through the year, he failed to readjust his game from the arcade style of the Cali League and saw his strikeout numbers balloon. He repeated the level in 2006 where he rebounded to hit .281/.335/.455. Johnson showed some developing power with 15 home runs, but with just 39 walks against 122 strikeouts, he was undisciplined at the plate. In addition, he swiped 20 bags in 38 attempts, showing a need to get better reads and jumps on the bases. Nevertheless, he was named the Southern League player of the year. Johnson capped his offseason by being selected as Tampa’s 20th best prospect by Baseball America prior to the 2007 season.
"His combination of speed and pop should enable him to stick in the majors, but his consistency will determine whether he becomes a starter or utilityman." - Baseball America, 2007 Prospect Handbook
With a year and a half of Double-A under his belt, the Rays promoted Johnson to Triple-A Durham where he promptly collapsed. A miserable season where he hit .207/.285/.341 caused him to vanish completely off the prospect radar in the deep Rays organization. Just 11 home runs and 43 walks versus 139 strikeouts painted the portrait of an impatient and sometimes overmatched hitter. He repeated Triple-A the next two years, showed some improvement, yet was removed from Tampa's 40-man roster. However, while he continued to show modest power, his plate discipline was raw. His base running had improved and he was proving versatile with the glove.
Continually blocked, he returned to Durham for 2010 and posted the finest season of his professional career. He hit .319/.375/.475 which were career highs across the board. He was rewarded with another turn on the Tampa 40-man roster an the International League MVP award.
Johnson's claim to fame in Tampa was as a central figure in the buildup to the Yankee-Rays rivalry. In a spring training game in 2008, he barreled into catcher Francisco Cervelli on a play at the plate and broke the Cervelli's wrist. Johnson claimed his play wasn't designed to injure, rather to gain the notice of management. It seemed to work, as he made the team out of spring training. Four days after the collision at the plate, Shelley Duncan slid spikes high on Akinori Iwamura at second and the benches cleared. A symbolic turning point in the Rays previously downtrodden history.
Although Johnson did have a cup of coffee in 2008, he made the big league club for good in 2011. It went about as good as you would expect for a middle infielder with limited plate discipline: .194/.257/.338 in 181 plate appearances.
In a bit of an upset, he made the team again in 2012. He saw more playing time, but again struggled with plate discipline and posted a line of .242/.304/.350 in 331 plate appearances. If you're going to struggle that much with the bat, you'd damn well better bring the leather. As Retro noted, Johnson has played all across the diamond. He's seen most of his action at shortstop and started for a stretch last year. He ultimately lost his role when they moved Ben Zobrist to short after bringing in Ryan Roberts in a trade from Arizona.
With roughly 1,000 major league innings at short, Johnson has been worth one net run according to The Fielding Bible. His fielding strength comes from moving to his right and he's adept at turning the double play. In limited samples, he looks like he wouldn't have difficulty with the double play relay while playing second. On first blush, it appears he would be the Royals best option defensively at second. That's not saying much. Let's call him average defensively, although the metrics were down on him last year. Overall, his defensive versatility is seen as a plus, but his lack of contact skill should keep him in a utility role. With 24 career steals in 38 attempts, the Royals have to love his speed. A switch-hitter, Johnson is much better from the left side of the plate so if you're thinking he could platoon with Chris Getz, stop.
In 2012, Johnson finished with a .290 wOBA which put him two points ahead of Mike Aviles who just signed a two year, $6 million deal. It ranked him 24th out of the 35 shortstops with at least 300 plate appearances. He struggled defensively, and finished with a paltry 0.3 fWAR.
Johnson is out of options, so it wouldn't make sense for the Royals to take him on if they don't think he can add to the roster. He will be the utility infielder when the Royals break camp. I'm fine with that, if only because that spares us the Miguel Tejada Experiment. Both Getz and Johnny Giavotella have options remaining, so I would assume the odd man out ships to Omaha. And we all know who's winning that battle.
Really though, Johnson is a Royals player. A Dayton Moore Special. He doesn't walk, has some speed and is adequately defensively. Most important, though... He's a gamer. A dirt dog. Against all odds, he scrapped, battled, dare I say gritted, his way though his professional career.