IMO, it has clearly been a single factor(emphasis added- there are other factors) that has disrupted the entire lineup. It is taking a long time for the lineup to adjust to his absence. I don't think the ideal lineup for the Sox is to have Pedroia batting leadoff, but no one else has laid claim to the spot. Pedroia has his biggest impact in the 3 hole. The best thing that can happen for the 2014 Red Sox offense would be for Sizemore or Bradley to step forward and show offensive consistency that could be used in the lead off spot.