INDIANAPOLIS -- The Atlanta Falcons are in negotiations to retain one-time Pro Bowl fullback Patrick DiMarco, but there is a strong possibility DiMarco could reunite with Kyle Shanahan in San Francisco.

DiMarco is one of 17 Falcons set to become an unrestricted free agent once the new league year begins next Thursday. He is one of the more valuable members of the group as a lead blocker for running backs Devonta Freeman and Tevin Coleman.

"We're in the process of talking to his representation, and we're hoping to have something finalized in the relatively near future," Falcons general manager Thomas Dimitroff told ESPN.com.

DiMarco previously expressed a desire to remain in Atlanta, but he also understands the reality of the business. The Falcons certainly won't overspend at the fullback position. DiMarco made $860,000 last season. Kansas City's Anthony Sherman topped all fullbacks in average per year based on the three-year, $7 million extension he signed in 2014 that included some $3 million guaranteed.

The Falcons will have competition for DiMarco. A league source said the 49ers are expected to make a push for DiMarco if he hits free agency. Shanahan, the Falcons' offensive coordinator the last two seasons and now the 49ers' head coach, valued DiMarco's contribution and needs a fullback to run his scheme.

DiMarco is one of a handful of Falcons headed to free agency that would make sense for Shanahan's system, a list that also includes quarterback Matt Schaub, wide receiver Aldrick Robinson, tight end Jacob Tamme and offensive lineman Tom Compton.

In other free-agent buzz related to the Falcons, defensive lineman Courtney Upshaw is expected to re-sign with the team next week. Upshaw was productive in limited playing time last season after signing a one-year, $1.25 million contract last offseason. His versatility could be an asset to what should be a revamped defensive line, although he needs to keep his weight down.

Also, word is the Falcons are making an effort to re-sign Schaub, and Schaub apparently would be willing to say if he's not guaranteed a starting spot elsewhere, such as in San Francisco. Schaub came to Atlanta to reunite with Shanahan and serve as the backup to MVP Matt Ryan.

Linebacker Paul Worrilow, who is expected to hit the open market, is likely to draw interest from at least four teams in a defensive role, not just on special teams. And tight end Levine Toilolo is unlikely to accept the Falcons' initial contract offer, although the terms of that offer were not disclosed.

The Falcons haven't ruled out re-signing veteran special-teams captain Eric Weems, but he won't be a priority.

Dimitroff said earlier in the week the Falcons were trying to re-sign safety Kemal Ishmael and Toilolo. Dimitroff essentially said the team was set to move on from veteran defensive tackle Jonathan Babineaux and Tamme.