Chase Utley holds the Phillies‘ chances of repeating a pennant and world championship… well, not in his hand, but in his reconstructed hip pocket. With Utley at full strength, something he really hasn’t been since last season’s All-Star break at latest, the Phillies could likely count on another MVP-level performance from the player who averaged .305/.385/.541 from 2005 to 2007. However, November surgery on Utley’s right hip has placed his readiness for the 2009 season in doubt, and even if he is ready to start the season, his ability to hit and field up to his previous high standards will remain an unknown.

Baseball Prospectus’s PECOTA forecasting tool predicted a .295/.377/.522 season in close to full-time play. This would be roughly consistent with Utley’s 2008 performance. Utley’s is a rare case where PECOTA is not dealing with a full set of information, however; it does not “know” about Utley’s surgery, an arthroscopic debridement of the labrum, nor the way that the hip injury affected the final tallies from Utley’s 2008 season. Having hit .360 with 11 home runs in April, Utley cooled considerably thereafter. Though he was able to maintain his batting average despite his discomfort, his power began to ebb. Utley hit his 31st home run of the year on August 22. Though he would bat .317/.423/.439 in the 33 games remaining in his season, he would hit just two more round-trippers.

In spite of the power outage, Utley was the Phillies’ most productive player last year, leading the team in value over replacement for the second straight season. He was also, for the fourth consecutive season, the most productive second baseman in the National League. The prognosis offered after his surgery was for a rehabilitation lasting four to six months. That placed Utley’s return anywhere from April 1 to June 1. At this writing, Utley seems to be on pace to be ready for the Phillies’ season opener on April 5, as he’s already taking grounders, running a bit, and taking some tentative swings for the first time since going under the knife.

Like the shoulder, the hip joint has a labrum, a ring of cartilage that adds stability to the joint by helping the femur maintain a solid connection with the hip socket. Symptoms of an injury include pain, weakness, and even degraded range of motion. In correcting for these problems, the surgery should make for a better Utley. The main concern for the Phillies is not diminished skills, but Utley’s availability at the end of a successful rehabilitation. When he becomes available, be it on Opening Day or at some later date, Utley should be the same player he was before the injury-though perhaps a small allowance should be made for his having joined the ranks of thirtysomethings with his birthday last December 17th. On the whole, the 30s are rarely kind to second basemen, as the wear and tear of the position begins to take its toll. Another intriguing question, one that cannot be answered until Utley sees game action, is if he altered his swing in any lasting way while attempting to compensate for the injury.

Should Utley miss significant time, the Phillies have a number of possible replacements in name if not in quality, including veteran utilitymen Eric Bruntlett (PECOTA: .241/.319/.324) and Miguel Cairo (PECOTA: .249/.311/.336), and former All-Star Marcus Giles, who took the season off after being cut loose in spring training by the Rockies. The boldest possible move the Phillies could make would be to advance one of their top prospects, shortstop Jason Donald, past Triple-A to the majors. Donald, 23, has been working out at second in case such a need should arise. A .297/.384/.459 hitter in 289 minor league games, Donald split last season between Double-A Reading and the Olympics, hitting .307/.391/.497 in 92 games with the former. PECOTA’s weighted mean projection for him is .248/.325/.397-not impressive, but almost certainly more than Bruntlett, Cairo, or the soon-to-be 31-year-old Giles (who hit .229/.304/ .317 for the Padres in 2007) would contribute. Bruntlett hits left-handers relatively well (.269/.358/.396 career), but there are only so many left-handers to go around. Cairo, most recently a key contributor to the Mariners‘ 101-loss season, hasn’t hit a home run since July 28, 2005. Last season, the average major league second baseman hit .276/.338/.409. None of these players, with the exception of Donald, is likely to come close, and even Donald’s forecast assumes that he’ll be able to skip past Triple-A without breaking stride.

Utley’s absence or inability to play at his established level would obviously throw a great deal of pressure back on former MVPs Jimmy Rollins and Ryan Howard, neither of whom were at their best last season despite the team’s championship. Both should be better this year, but are unlikely to improve to such a degree that the most valuable second baseman in the game would not be missed. At other positions, the Phillies can expect consistency at best, which means that, as he was in 2007 and 2008, Utley is the key to the Phillies’ entire offensive attack.

Again, the good news is that if anything, a more stable hip should mean an Utley with his power stroke restored. PECOTA already predicted a difficult path back to the playoffs for the Phillies, seeing them as substantially inferior to the Mets and about the equal of the Braves and Brewers. A damaged or diminished Utley would reduce their chances still further, but as of right now there is substantial reason for optimism.