It will be Jackson's seventh team, and the question is whether the Nationals can change his delivery so that his command can be more consistent.
Jackson, 28, was a top-notch pitching prospect who started with the Los Angeles Dodgers, but his lack of command has been the reason he hasn't lived up to his billing.
Last season, with the St. Louis Cardinals, Jackson pitched well, but Cardinals pitching coach Dave Duncan was working with Jackson to keep from tipping his pitches and being more efficient. Jackson missed the strike zone too often early in the count.
Nats general manager Mike Rizzo said that the team has some ideas on how to change Jackson's delivery to make it more difficult for opposing batters to pick up his pitches.
With the Cardinals last season, Jackson was 5-2 and gave up 91 hits in 78 innings. He had 51 strikeouts and 28 walks with the Cardinals. He had only one bad start for the Cardinals, his first after a trade, when he gave up 14 hits and 10 runs in seven innings versus the Milwaukee Brewers.
Jackson, an all-star with the Detroit Tigers, pitched a no-hitter in 2010 in a game he walked eight. It was a snapshot of his career.
Jackson, who throws a fastball, slider and curve and occasionally a changeup, has moved around plenty. But, he's 28 years olds with a power arm.
And, the fact that he's been traded for big-time prospects, such as Colby Rasmus, Daniel Hudson, Austin Jackson and Matt Joyce, speaks to his potential for the Nationals.