Utley_sittingNobody seems to know when Utley will take the field in 2011

Another week has passed and still nothing definitive on Chase Utley.  Like many other fans, the potential seriousness of Chase Utley's knee injury has put a little bit of a damper on the season for me so far. And Wilson Valdez hasn't even hit into any rally-killing double-plays yet. But then I recalled the hot streak the Phils went on from late July to mid-August last season, with Chase out of the lineup. As Rich Hofmann noted recently, it turns out the Phillies actually had a better winning percentage in the 47 Chase-less games last season, than they did with him in the lineup, compiling a 29-18 record (.617 winning pct) without him and a 68-47 record (.591) with him.

You're probably guessing that the pitching carried them when Utley was out more so than when he was in the lineup. Well, the stats don't really back up that premise. In the 47 games Utley didn't play, the staff ERA was 3.58. In the 115 games he did play, it was 3.70, or 0.12 more runs per game. At that rate, that's only about six less runs over the 47 games without Utley than they would have allowed on average with Utley. Six runs in 47 games. 

Not surprisingly, their offensive production was a little better overall with Utley. Just looking at the bottom line runs scored per game, they scored 4.51 in the 47 games without Utley vs. 4.87 with Utley. The per game run-differential was +0.93 without Utley and +1.17 with Utley.
I usually question how statistically significant small fractions of a single run can mean over any stretch in baseball. And it is difficult to isolate just Utley's impact on the offense, when you consider that Ryan Howard and Shane Victorino also missed several games while Utley was out, which definitely affected the overall offensive output. Polanco and Ibanez being on hot streaks when Utley was out to make up for this, may have made up for that.
Obviously, a healthy Utley would perform at a higher level than anyone who would replace him. And without Werth in the middle of the lineup, his absence will have even more of a ripple effect than last year. But with the Four Aces, they are much better-equipped to survive prolonged offensive slumps or overcome significant injuries to their position players. They are ultimately replacing every 2010 Kyle Kendrick start with Cliff Lee and 2/3 of Jamie Moyer's 2010 starts with Roy Oswalt. 
So, I believe they will be fine if Utley misses an extended period of time. In fact, if a surgical procedure would likely solve the problem in the knee for now, but shelve him for 3-4 months, they would have to strongly consider it. Having a healthy Utley return to the lineup in July would likely give the lineup the same type of boost as acquiring a bat at the trade deadline would. As long as he's back for the stretch drive, they will be fine.