Nationals trade for Gio Gonzalez

The Nationals took a major step toward contention on Thursday, acquiring left-hander Gio Gonzalez from the Athletics for four prospects.

The Nationals today also acquired right-handed pitcher Robert Gilliam in the deal. In return for Gonzalez, the Athletics will receive catcher Derek Norris and three highly regarded pitchers — right-handers A.J. Cole and Brad Peacock plus lefty Tom Milone.

The addition of Gonzalez gives the Nationals a young, formidable trio at the top of their rotation — right-handers Stephen Strasburg, Gonzalez and righty Jordan Zimmermann.

Lefty John Lannan likely will be the fourth starter, with lefty Ross Detwiler and righty Chien-Ming Wang also are candidates to start.

Gonzalez, 26, averaged 16 wins, 202 innings and a 3.17 ERA his past two seasons with the Athletics. He is under club control for four more years. One concern: He led the American League walks in 2011.

The Red Sox and Marlins were among the other most aggressive suitors for Gonzalez. The Rangers also were heavily involved before they won the negotiating rights to Japanese right-hander Yu Darvish.