Former Washington Nationals pitcher Edwin Jackson is close to signing a four-year, $52 million deal, according to Buster Olney of ESPN.com.

Jackson tested the free-agent waters last season too, but did not receive the same level of interest last season as he has this year. The right-handed starter signed a one-year, $11 million deal with the Nationals, who chose not to offer him a one-year, $13 million dollar qualifying offer. If they had made the offer and Jackson refused it, Washington would have received a first-round draft pick when Jackson signed elsewhere.

The Nationals chose to sign former Los Angeles Angels starter Dan Haren to a 1-year, $13 million deal as Jackson's replacement for next season.

Jackson started 31 games last season, his sixth straight season starting at least 31 games. Jackson posted a 4.03 ERA and 3.85 FIP in 189 2/3 innings last season. The 29-year-old starter also recorded the highest strikeout percentage of his career while keeping his walk rate in check.