Starting Monday, the Patriots will have a two-week window to place a franchise tag on one of their free agents. This decision is significant on a number of levels. It will have a bearing on their most pressing needs in free agency and the draft. Whom will the Pats designate, if anyone at all? They aren’t obligated to exercise that option. In the six years the NFL has offered use of a tag, the Pats have gone that route every year but 2008 and 2010. Scanning the list of possibles this time out, there are three candidates to consider. Here’s an assessment on each: Wes Welker Pro: It’s hard to debate the numbers and what Welker has provided the Pats offense. The slot machine just keeps producing and getting open underneath. He also keeps getting up after taking a pounding. He’s an automatic 100-plus catches every year. That kind of production isn’t easily replaced. Neither is his connection with Tom Brady. Keeping Welker in a Pats uniform would keep both happy. Welker is the chains-mover. He keeps Brady and the offense in sync. Or, as Brady said about Welker, he’s the “heart” of the team. Assigning the tag will, at the very least, keep the team moving toward a multi-year extension at a more reasonable cost. Con: The franchise number for Welker is $11.4 million, given he was tagged last season. That’s a huge hit on the Pats for a receiver who turns 32 in May. He’s also made a few critical drops in big games. As great as he’s been, those factors are tough to overlook. Now, if the desire is to keep Welker and sign him to a multi-year deal at a more reasonable rate, extending the tag and having him sign could potentially lock them in at an unfriendly cap figure, much like last season when a longer deal wasn’t worked out. Do the Pats really want to risk paying him $11.4 million? Not extending the tag and having him establish his price in free agency — something the Pats ultimately could match — might be a better way to go.