Gio Gonzalez was an all-star last season with Oakland, going 16-12 with a 3.12 ERA in 202 innings. With his contract extension, the Nationals will be able to keep him through 2016 and perhaps 2018. (Paul Beaty/Associated Press)

The Washington Nationals made a long-term commitment to their biggest offseason acquisition, signing left-handed pitcher Gio Gonzalez to a contract extension through the 2016 season with team options for 2017 and 2018.

The extension, which the Associated Press reported was worth $42 million, will cover Gonzalez’s four arbitration-eligible seasons, as well as at least the first of three seasons of being eligible for free agency.

The Nationals reached their long-term deal with Gonzalez less than a month after they sent four prospects to the Oakland Athletics to acquire him. With right-handers Stephen Strasburg and Jordan Zimmermann under team control through 2016 and 2015, respectively, the Nationals have assembled one of the most desirable 1-2-3 rotation combinations in baseball.

“Gio’s ample talents are well known and chronicled,” General Manager Mike Rizzo said in a statement released by the team. “Today’s extension was about comfort for both parties. From our end, the two option years and team control were imperative to the extended commitment.

“Now both Gio and our fans can shift their focus and excitement to his debut in D.C. knowing that their relationship won’t be ending in the short term.”

Gonzalez, 26, has emerged as one of the best young starters in the league. He was an all-star last season, going 16-12 with a 3.12 ERA in 202 innings, striking out 197 batters and walking 91.

In late December, the Nationals traded pitchers A.J. Cole, Brad Peacock and Tom Milone and catcher Derek Norris to Oakland for Gonzalez. General Manager Mike Rizzo said he was motivated to make the trade because of the many years of team control Gonzalez had.

By extending him, the Nationals guaranteed he’ll be a part of their future for years to come. Gonzalez is the only Nationals player whose current contract could run through 2018. Jayson Werth, under contract through 2017, has the longest contract on the team otherwise.