Vollmer the priority?

Despite having several key members of their core locked in to long-term deals, the New England Patriots do have some significant players set to hit free agency if the Pats do not work out a new deal with them. Included in the cohort are WR Wes Welker, CB Aqib Talib and RT Sebastian Vollmer. There are pros and cons to re-signing each of them, but who will be the priority?