The Patriots are putting in work this week in case they’ve got to find a replacement for right tackle Sebastian Vollmer in April’s draft. Vollmer is set to become an unrestricted free agent on March 12, and unless the Patriots hit him with the franchise tag for a projected $9.66 million, there is a strong possibility he will be unleashed in the open market. From there, teams could bid on Vollmer for a heftier left tackle price tag while the Pats will try to retain him at a right tackle cost. That line of thinking isn’t favorable for a reunion between the Pats and Vollmer, a second-round pick in 2009, which could be why the Patriots have already spent time with some of the 2013 draft class’ most esteemed tackles. While Texas A&M’s Luke Joeckel and Central Michigan’s Eric Fisher could be off the board in the first few picks, the Pats have spent some quality time with the next tiers, which are still undefined. Colorado’s David Bakhtiari had a formal meeting with the Patriots last night, while Wisconsin’s Ricky Wagner and Syracuse’s Justin Pugh are among the tackles who had earlier interviews with Pats scouts. Bakhtiari, who declared after his redshirt junior season, was given a second- or third-round grade by the league’s scouting service, and has close ties with the Pats. He was Colorado’s starting right tackle as a redshirt freshman when Nate Solder was the starter on the left side. Solder became Bakhtiari’s closest mentor and had him out to Foxboro for a visit when the Patriots hosted the 49ers in Week 15. Bakhtiari, who is 6-foot-4 and 299 pounds, doesn’t have ideal size for a tackle but said he had no problem playing any position on the line. That versatility would make him highly endearing for the Patriots.