With Matt Holliday rolling to a 1.235 OPS in 31 at bats since the All-Star break, Billy Beane reached a deal to send the left fielder to the St. Louis Cardinals in exchange for third baseman Brett Wallace, outfielder Shane Peterson and right-handed pitcher Clayton Mortensen. Oakland almost had to deal Holliday because they could have been stuck with a huge one-year price tag with arbitration. I was in Oakland for his 4-for-5, two homer night on Monday against the Twins and he didn't look like an .832 OPS kind of hitter. I'm still suspicious of his .801 career OPS in away games, but he is unquestionably a better player than he was during his brief, ill-fated stint with the A's. The A's had delusions of competing this season, as they boldly dealt for Holliday while signing Orlando Cabrera, Jason Giambi and Nomar Garciaparra. From the outset of their season, it was clear that this was a lineup incapable of scoring enough runs to support a young pitching staff. But acquiring Holliday was still the right move because he had two fallback options; taking two compensatory picks in next year's draft or trading him away before the July 31st deadline. They have now essentially dealt Huston Street, Carlos Gonzalez and Greg Smith for Brett Wallace, Shane Peterson and Clayton Mortensen, which is overall probably a small net gain. Street has had a resurgence in Colorado, with his best park adjusted ERA of his career, a WHIP below 1.000 and a strikeouts per nine innings rate over 10. Gonzalez absolutely tore up the Pacific Coast League in 192 at bats, posting a 1.048 OPS before being called up in June where he has had everyday duties to mixed success. He is better suited for Coors Field and National League baseball than he is for Oakland's system. Smith's 2009 has been an unmitigated disaster in his various minor league stops. Brett Wallace is clearly the key to this deal for Oakland. He was selected 13th overall a year ago, grew up in nearby Napa and swings a very big bat. There was a lot of support for the A's to draft Wallace instead of Jemile Weeks and now they have both players a little over a year later. He came into 2009 as the Cardinals best prospect not named Colby Rasmus, but he has had a relatively disappointing 2009, combining to hit .289/.368/.429 in stops at Double and Triple-A. He will turn 23 next month, so the answer on what kind of ceiling he has will become clear very soon. The A's intend to leave him at third base, but he doesn't have the chops to stay there long-term. Mortensen is another former top draft pick, selected 36th overall in 2007. He has a career 4.30 ERA in 305.1 minor league innings. His strikeout rate has hovered around seven and is known for featuring an excellent sinker. Peterson was selected 59th overall in 2008 and has a .784 OPS this season. He fit Oakland's high OBP model when he was in college, but that hasn't translated during his first forays in the minors. Grade for Oakland: B+ The Cardinals had more than enough talent to win the NL Central before this trade and now they quickly emerge as the prohibitive favorite. Left fielders had produced a season OPS of .635 for the Cardinals, while clean-up hitters weren't much better, posting a collective OPS of .768. Holliday will significantly improve both slots. He also will produce more swing opportunities for Albert Pujols, who has severely lacked protection in the lineup. The impact of having Pujols receiving challenge pitches makes the lineup significantly more dangerous. Holliday is also a notoriously strong finisher, with a career second half OPS of .964 compared to .898 for the first half. The Cardinals will have the advantage in re-signing Holliday, a Scott Boras client who rejected a $72 million extension offer over four years from the Rockies. They will surely offer arbitration and be guaranteed to recoup picks for the rental as a worst case scenario. Grade for Cardinals: A