"A year ago, Washington Nationals General Manager Mike Rizzo was prepared to trade four young players to the Kansas City Royals for former Cy Young winner Zack Greinke, the deal falling apart only because Greinke, with a full no-trade clause, refused the Nationals' nine-figure contract offer in exchange for accepting the trade.

But the Nationals' thirst for a front-line starter to join Stephen Strasburg and Jordan Zimmermann atop their rotation never lessened, and Thursday the team agreed in principle to a blockbuster deal for Oakland Athletics all-star lefty Gio Gonzalez in exchange for four of their best prospects. Keith Law of ESPN.com first reported details of the trade, which is pending physicals and likely won't be announced officially until at least Friday.

In exchange for Gonzalez, a 26-year-old who has won 15-plus games and thrown 200-plus innings in each of the past two seasons, the Nationals are giving up three pitching prospects — right-handers Brad Peacock and A.J. Cole, and lefty Tommy Milone — plus catching prospect Derek Norris. Peacock, Cole and Norris ranked third, fourth and ninth, respectively, in Baseball America's recent list of the Nationals' top prospects. All four were drafted in the fourth round or higher."