Chris Carpenter was the Blue Jays' number one pick in the 1993 draft who, according to the 1997 Baseball Prospectus, had "scouts drool[ing] about his makeup as much as his sinking fastball and power curve." Carpenter made his big-league debut in 1997 at the age of 22 and was a part of the Blue Jays rotation until 2002, when his season was derailed by a SLAP tear to his labrum that required a surgical repair. This made him the quintessential Walt Jocketty dumpster dive.
The SLAP tear was thought to be "minor," according to the 2003 Baseball Prospectus, and the Blue Jays had hoped to sign the righty to a minor-league deal but the Cardinals signed Carpenter away from Toronto before the 2003 season. This damaged piece of scrap off the heap required still more repair, however, in the form of scar tissue removal from his shoulder post-surgery, and Carpenter did not throw a pitch for the Cardinals in 2003. The removal of scar tissue did the trick and Carpenter pitched well for the Cardinals in 2004 until "nerve irritation" ended his season in September. The Baseball Prospectus injury page describes it as a "neurological injury" to the musculocutaneous nerve of his right upper arm.
Carpenter came back from the nerve irritation with a vengeance in 2005, winning the National League Cy Young Award with a statistical line featuring a 2.83 ERA (68 ERA-), 2.90 FIP (69 FIP-), 7.93 K/9, 1.90 BB/9, 6.8 fWAR and 21 pitching "wins" (if you're into that sort of thing). In 2006, he was the bright spot in a truly horrendous pitching staff that the Cardinals made the postseason in spite of and miraculously won the World Series because of. On Opening Day 2007, Carpenter exited the game after 6 innings pitched. He wouldn't make another start that season. Elbow irritation led to a surgical procedure to remove bone spurs. That procedure was followed by Tommy John surgery on July 24, 2007, for the replacement of the ulnar collateral ligament. The road back from Tommy John surgery was a bumpy one.
Carpenter made his first rehab start on July 20, 2008, nearly a year after undergoing Tommy John surgery. He made three starts for the Cardinals before a shoulder strain sidelined him again. In the midst of a bullpen meltdown, the Cards called on their former ace as a reliever. Carpenter had problems bouncing back from that outing and was shutdown for the year due to "nerve irritation in the shoulder," according to the 2009 Baseball Prospectus.
Carpenter was suffering from nerve compression in the shoulder of his musculocutaneous nerve, which, as Chris Neault of Baseball Prospectus noted at the time, "sure sounds similar" to the condition that ended Carpenter's 2004 season, "especially since this nerve serves the biceps muscle, the very same muscle that apparently caused his nerve irritation in 2004." Neault also discusses the treatment options discussed and the one that was eventually chosen to deal with the problem.
As a result of his symptoms, surgery was being considered as an option to release the nerve from its compression. But after Carpenter received four opinions from various specialists, it was decided that he would not have the surgery because there was no guarantee that it would alleviate his symptoms. In addition, the specialists felt that the risks were too great.
Later, in November of 2008, Carpenter underwent another surgical procedure, this one for ulnar nerve transposition. As Will Carroll later wrote in his Under the Knife column at Baseball Prospectus, this was somewhat surprising because it is common for surgeons to transpose the ulnar nerve when performing a Tommy John surgery to avoid the very complication from which Carpenter experienced. Carpenter's surgeon did not do this so a second procedure was performed.
On November 30, 2008, Carpenter did an interview with David Laurila of Baseball Prospectus. One of the first questions dealt with Carpenter's health status; to which, Carpenter answered:
My elbow is feeling good. I just had a little simple surgery to move a nerve, so I’m feeling good. The doctors don’t feel that it’s going to be an issue. As for my shoulder, time will tell. When I get back to St. Louis, after this event, I’m going to get some tests done, and some nerve conduction studies done, to see how my nerve is healing. Nerves take time to heal, but I think that everybody believes that I’m going to be able to come back and pitch, it’s just a matter of how long before that happens.
Despite the unique combination of post-Tommy John complications featuring both the shoulder and the elbow, Carpenter again bounced back. In 2009, he placed second in the National League Cy Young voting with a 2.24 ERA (55 ERA-), 2.78 FIP (67 FIP-), 5.6 fWAR, and 17 pitching "wins" in 28 starts (which gave him a league-leading .810 "winning percentage"). In 2010, Carpenter fell back down to earth a bit but was still solid (3.7 fWAR). Last season, he carried a Wainwright-less pitching staff on a club that improbably won its eleventh World Series title by helping to secure the Wild Card with a complete game shutout of the Astros on the season's final day, outdueling Roy Halladay in the decisive 1-0 Game 5 of the NLDS, and by winning Games 1 and 7 of the World Series.
Carpenter totaled 273 innings pitched between the regular season and postseason. This established a new career high in innings pitched, surpassing the 262.2 innings he tallied in 2005. Carpenter also pitched 254 innings during the Cardinals' 2006 World Series run, bringing his two-year total for 2005 and 2006 to 516. In 2010, Carpenter threw 235 innings, which makes his two-year total leading into this season 508 innings. With his high innings-pitched total and injury history, perhaps Cardinals fans should not be too surprised that Carpenter is seeing doctors in St. Louis about a nagging neck condition that may be yet another bout of the ominously vague "nerve irritation" that ended his 2004 season and sprung up again in 2008.
Jenifer Langosch of stlcardinals.com has tweeted that there is still no word from the Cardinals regarding Carpenter's condition and that an update may take place before the end of the day. If the doctors in St. Louis find nothing in addition to the already-made diagnosis of a bulging disc, Cardinals fans should breath a sigh of relief for, if this is another bout of "nerve irritation," Carpenter's future as an effective starter is much murkier.