It is absolutely the # 1 reason - without him we do not make the post-season.
I know that our starters were injured - but our offense around ASB was so bad - it was threatening to be one of the league worst. Bay was in huge slump and so was Ortiz. Somehow - VMart became the castalyst that bought the offense to very respectable.
Getting V-Mart is a nice feather on Theo's otherwise dismal record with trades. Not sure how the prospects and Masterson will work out in futrure - but in short term - he became Red Sox savior 2009.