Last year, the Cardinals won a world championship despite losing co-ace Adam Wainwright to a torn ulnar collateral ligament even before the start of exhibition season. So when their other co-ace, Chris Carpenter, went on the shelf this spring with neck and shoulder weakness, the loss didn't appear to be a critical one, particularly with Wainwright returning from Tommy John surgery; once healed, Carpenter would join a rotation that could be stronger than last year's model. Alas, after being diagnosed with thoracic outlet syndrome, it appears as though the 37-year-old righty won't throw a pitch for the 2012 team. His Monday bullpen session was canceled, and he's now scheduled to undergo season-ending surgery on July 19. While unfortunate, the timing of his loss leaves the Cardinals ample time to bolster their rotation for a playoff push.
Since bolting out to a 20-9 start that gave them a 3 1/2 game lead in the NL Central, the Cardinals have been limping along, going just 22-27. Even so, at 42-36, they're in third place in the division, just 2 1/2 games behind the Reds, and 1 1/2 games out of Wild Card spot; their +63 run differential is the NL's best. While Wainwright has been roughed up for a 4.75 ERA in his return — largely due to a .332 BABIP, not the typical post-Tommy John surgery command woes — the rotation has actually fared well in Carpenter's absence, with a 3.82 ERA (sixth in the league) and 58 percent quality start rate (ninth, but slightly above average) thanks in large part to a league-low home run rate (0.75 per nine) and the third-lowest unintentional walk rate (2.3 per nine).
Even so, the unit could stand reinforcement. Lance Lynn, who has filled in for Carpenter, has emerged as one of the season's biggest surprises via a 3.62 ERA and a sizzling 9.1 strikeouts per nine, a showing that earned him a spot on the NL All-Star team. His tendency to pitch deep into counts has him fourth in the league at 4.02 pitches per plate appearance, and the 97 innings he has under his belt aren't far from last year's total of 109 2/3. Drubbed for 17 runs in 15 1/3 innings over his last three starts, he may already be dealing with fatigue. Kyle Lohse has pitched to a staff-best 2.80 ERA despite striking out just 5.2 hitters per nine; if his .270 BABIP regresses — a good possibility on a team that's seven points below average in Defensive Efficiency — his ERA will rise. Jaime Garcia was hit for a 4.48 ERA before being shut down in early June due to rotator cuff tear that's causing impingement; he'll miss a minimum of two months, and could face season-ending surgery himself. Rookie Joe Kelly, who has taken over for Garcia, has whiffed just 4.6 per nine in four starts; he's got an outstanding hard sinker, but command issues and the mediocrity of his secondary offerings limit his ceiling.
As for Carpenter, this is just the latest low point in a rollercoaster 10-season stint with St. Louis that has seen its share of extremes. A torn labrum wiped out his first year with the Cardinals back in 2003, while bone spurs and Tommy John surgery limited him to five appearances in 2007 and 2008. Even amid more minor injuries, including shoulder and oblique strains, a 2004 nerve issue that left him off the postseason roster, and a 2008 episode of numbness in his arm that's said to be related to his current woes, he has excelled when he's made it to the mound. His 3.06 ERA as a Cardinal is the majors' third-best among pitchers with at least 1,000 innings since 2004, narrowly behind Johan Santana and Roy Halladay, and along the way he's earned three All-Star appearances, the 2005 NL Cy Young award and two other top-three finishes while helping his team to five playoff berths, three pennants and two world championships. He has gone 9-2 with a 3.05 ERA in 15 postseason starts, including six strong innings against the Rangers in Game 7 of last year's World Series. That's an ace.
The thoracic outlet syndrome Carpenter is experiencing is a rare problem in which nerves and blood vessels are compressed in an area between the collarbone and the rib cage, causing numbness in the arm. The condition is alleviated via removal of the uppermost rib, and typically requires a six-month recovery. Because of the way pitchers twist their heads towards the plate, they're at higher risk for TOS; hurlers such as Jeremy Bonderman, Aaron Cook, Matt Harrison, Noah Lowry, Kenny Rogers and Kip Wells have dealt with the condition with varying degrees of success since 2000, as have position players such as Hank Blalock and Jarrod Saltalamacchia. Assuming a timely surgery, Carpenter should be ready for spring training in 2013 and the final season of his two-year, $21 million deal. While his loss is a blow to the Cardinals, the certainty that he's done for the year should allow general manager John Moleziak and the rest of the organization a more clear-eyed assessment as the trading deadline approaches; unlike Lance Berkman, who's due back after the All-Star break, he's not part of the cavalry that's going to ride in to the rescue. The team isn't likely to be players for the Phillies' Cole Hamels or the Brewers' Zack Greinke — the latter is almost certain not to be dealt within the division, if at all — but St. Louis does have a strong farm system, and as last summer's acquisition of Edwin Jackson showed, it won't necessarily take an ace to put this team over the top.