By Matt Snyder

The Washington Nationals have landed left-handed starting pitcher Gio Gonzalez, CBSSports.com insider Jon Heyman has confirmed. In return, the A's will receive a veritable killing that is usually reserved for an ace-type pitcher. Tommy Milone, Brad Peacock, Derek Norris and A.J. Cole are headed to Oakland's system in a trade that was first reported by ESPN.com. In fact, Peacock and Milone are probably going to be thrown into the A's starting rotation. UPDATE: CBSSports.com's Scott Miller reports that the Nationals will also get right-handed pitcher Robert Gilliam.

"It's 99 percent done," Gonzalez said (Associated Press). "It's pending a physical and I'm just waiting to hear from my agent."

On the Washington end, they are getting a 26-year-old lefty who isn't eligible to be a free agent until 2016. Gonzalez was 16-12 with a 3.12 ERA and 197 strikeouts in 202 innings last season for the A's. Of course, he also led the majors with 91 walks. Still, he's pretty tough to hit, holding opposing hitters to a .230 batting average and .336 slugging percentage last season.

With Gonzalez alongside Stephen Strasburg and Jordan Zimmermann, the Nationals have a formidable trio to lead their rotation for several years. Further, with John Lannan and Chien-Ming Wang -- and Ross Detwiler as insurance -- the Nats have a very strong rotation top to bottom. They are coming off their best NL East finish since the move to Washington -- third place -- as they'd previously finished in last place five times and fourth place once.

Gilliam, 24, appears to be a throw-in. He was 12-7 with a 5.04 ERA and 1.30 WHIP in High-A ball last season. He did strike out 8.5 batters per nine innings, though.

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As for the A's, they are clearly rebuiling, just as we've known all winter. They already traded All-Star pitcher Trevor Cahill to the Diamondbacks and are still rumored to be close to trading closer Andrew Bailey.

This deal will go a long way toward setting up the future, and -- as I mentioned earlier -- Milone and Peacock probably step into the rotation with Brandon McCarthy and two others (Brett Anderson and Dallas Braden are still recovering from season-ending surgeries) immediately.

Milone is a 24-year-old left-hander. He was 12-6 with a 3.22 ERA, 1.03 WHIP and 155 strikeouts in 148 1/3 innings in Triple-A last season. He was then promoted to the big-league club and made five starts, with decent success. He had a 3.81 ERA and 1.25 WHIP in 26 innings with 15 strikeouts and four walks (and two of those were intentional).

Peacock was pretty dominant last season at three different levels. The 23-year-old right-hander started the season in Double-A, where he went 10-2 with a 2.01 ERA, 0.86 WHIP and 129 strikeouts in 98 2/3 innings. He then struck out a batter per inning in Triple-A for nine starts and was moved up to the Nationals. In 12 big-league innings, Peacock only gave up seven hits and one run (0.75 ERA).

Norris, 22, is a high-on-base, power-hitting catcher. Last season, he hit just .210 but had a .367 on-base percentage with 20 home runs in Double-A. He also stole 13 bases and threw out 40 percent of would-be base-stealers.

Cole, 19, is a bit away from the bigs but has high upside according to many scouting services. The 6-foot-4 right-handed pitcher went 4-7 with a 4.04 ERA for Class-A Hagerstown last year, but he also struck out 108 batters in 89 innings.

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