The Patriots and Wes Welker have plenty of sentimental and strategic reasons to work something out and sign a new deal, but perhaps the biggest factor that could keep Welker in New England is something else entirely: cap space — and not for the Patriots.

Every NFL team is struggling to sign players and stay under the cap, and the upcoming free agent season is expected to push some deals through the roof and limit what teams can offer, Greg Bedard of The Boston Globe cites league sources as saying. Bedard points to this as a major reason why Welker and the Patriots, who are already interested in renewing their relationship, will be able to pull off a deal.

Bedard discounted recent reports that the Patriots and Welker are having trouble reaching an agreement, calling a deal “not a matter of if, but when.” He says sources “on both sides of the Welker situation” indicate that “he will be back with the Patriots.” Bedard says that, while other teams may make a run for Welker, he’s not at the top of the free agency heap and would be unlikely to get the money he wants from another team.

Bedard also says there’s a chance that the team will back down on the amount of guaranteed money it will offer Welker, which is a big factor for the 31-year-old. But, overall, he says the Patriots are unlikely to move on from the proven receiver as they look to strengthen their offense with an outside threat.

Bedard also addressed recent reports about Welker’s unhappiness with the team after his reduced involvement with the offense early last season. He said Welker and the Patriots ended the year on a good note, and that Welker did not air his grievances publicly or among the team, which would earn points with New England.

Free agency begins March 12, but teams can start talking with players Saturday.