Price was high, but Nats finally get workhorse arm in Gio Gonzalez (updated)

There are all kinds of reasons to make a trade - you're trying to fill a hole, you're trying to loosen a positional logjam, you need to create a pathway for a promising young player. The Nationals' acquisition Thursday afternoon of left-hander Gio Gonzalez from the Oakland A's in exchange for four prospects solves a glaring need in the Washington rotation: someone to log lots of innings and take the pressure off younger starters coming off injuries. Both sides have agreed in principle to the parameters of the trade, leaving physical examinations and the exchange of medical information the only roadblocks to a formal announcement. Keith Law of ESPN first reported the trade on Twitter. General manager Mike Rizzo began laying the groundwork for Gonzalez's arrival at the Winter Meetings in Dallas, but when he spoke to reporters about his meetings with Oakland GM Billy Beane two weeks ago, it sounded as if talks were in the kick-the-tires stage. Because he's only 26 and under team control through 2015, Gonzalez was coveted by at least a dozen teams, especially those not willing to spend big bucks on free agents like Mark Buehrle and C.J. Wilson, or shell out exorbitant posting fees and engages in equally expensive contract talks with Japanese wunderkind Yu Darvish. What set the Nationals aside from other potential suitors for Gonzalez, who went 16-12 with a 3.12 ERA in 32 starts last season? The bevy of promising young talent Rizzo (and before him, Jim Bowden) has been collecting for the past handful of years finally paid off in spades. The price was significant - right-handers Brad Peacock and A.J. Cole, lefty Tommy Milone and catcher Derek Norris - but Washington was dealing from a position of depth to fill a need. Gonzalez's arrival will give the Nationals a starting five of Stephen Strasburg, Jordan Zimmermann, Gonzalez, Chien-Ming Wang and John Lannan entering 2012 (barring, of course, any subsequent trades). Strasburg will be limited to around 165 innings in his first full season after Tommy John surgery, and Zimmermann is only one full campaign removed from a similar procedure and and a comparable cap. Wang missed most of the past two seasons recovering from shoulder ailments that threatened his career. Lannan is durable, but fits better at the end of a rotation, not as a No. 1 or No. 2. With Gonzalez, the Nationals have an affordable option that will keep the top three arms in their rotation under team control through 2015, providing time for the next wave of prospect pitchers to develop. Gonzalez is arbitration-eligible and will probably command a salary of north of $4 million this season, with rises likely unless Rizzo can negotiate a long-term deal with him. When their run at Buehrle ended with the free agent signing with the Marlins, talks between the Nationals and A's intensified and Oakland, unable and unwilling to pay the rising cost of keeping a premier starter, was willing to deal him. Peacock, who overachieved as a 41st-round selection in the 2006 draft, and Milone, a 10th-round pick in 2008, got late-season auditions last season that were just as much showcase opportunities for other clubs. The Nationals didn't want to part with both, but it's easier to trade prospects with high ceilings when you're hopefully looking into the future. Norris (2006) and Cole (2010) were both fourth-rounders, a potential catcher of the future with a high on-base percentage and a longer-range rotation righty. Both teams get what they want in this exchange: The Nationals acquire a workhorse who has twice won 15 games, logged 200 or more innings and posted an ERA of 3.23 or lower; the A's gain payroll flexibility, young talent and part with one player while getting four in return. It's difficult not to see this as a win-win proposition benefiting both sides in both the short and long term. Last weekend's trade of the Padres' Mat Latos to the Reds for four players, including three former first-round draft picks, elevated the bar for the Gonzalez swap. Peacock, Cole and Norris were the Nos. 3, 4 and 9 of the Nationals' top 10 prospects in Baseball America's recent rankings. Gonzalez isn't a perfect pitcher. He walked an American League-high 91 batters in 2011 and has issued 183 free passes over the past two seasons, when he was 31-21 in 55 starts, and he's prone to lapses of concentration on the mound. What will be asked of him in D.C., with a team on the precipice of contention in the tough National League East, will be much different from his job description in Oakland. Update: According to multiple published reports, the Nationals will also receive right-hander Robert Gilliam in the deal. The 24-year-old, an eighth-round selection by the A's in the 2009 draft, spent 2011 at Single-A Stockton, where he went 12-7 with a 5.04 ERA in 28 starts.