According to ESPN.com, Welker will begin testing free agency this week.
In five of the six seasons Welker has spent with the Patriots, he has caught more than 100 passes and gone for more than 1,100 yards. That is difficult consistency to find.
More importantly, it's not how much Welker does catching the ball, it's more how he makes everyone better. This is a New England offense that thrives spreading the defense out both passing and running the football.
Welker is a guy that New England can put both in the slot or on the outside, depending on the formation. With Rob Gronkowski and Aaron Hernandez as significant threats lining up at both tight end and in the slot, there are too many looks the defense has to worry about.
Then in the running game, Welker serves as a perfect decoy on second down. Tom Brady will line up under center, spread everyone out (including the defense) and simply hand the ball off to whichever running back is on the field.
There's also the chemistry factor between Welker and Tom Brady.
This duo has been paired together for the last six seasons, and Brady recently signed a contract extension through the 2017 season (via Brian McIntyre of Yahoo! Sports). Brady is 35 years old and will turn 36 on August 3 before the 2013 season begins.
Welker has always been a guy Brady can quickly audible to at the line of scrimmage or send a hand signal to for an option route. It's not like Brady isn't capable of being on the same page with another receiver, but what he and Welker have is tough to replicate in a short amount of time.
Considering that Brady has lost his last two Super Bowl appearances and Welker is still seeking his first ring, both players need each other to finish what they started together.
New England needs to find a way to retain its ace receiver.