It will be far from the biggest move made around the league in free agency, but fullback Patrick DiMarco heading to the Buffalo Bills is a significant loss for the Atlanta Falcons.

Sure, fullback is an undervalued position in today's game, and most folks would say you can find a replacement anywhere on the street. The reality is DiMarco, a one-time Pro Bowler, played a crucial role in the Falcons' offensive success the last few seasons.

DiMarco served as a lead blocker to running backs Devonta Freeman and Tevin Coleman. Last season, Freeman surpassed 1,000 rushing yards for the second consecutive year and had 11 rushing touchdowns, while Coleman scored eight rushing touchdowns. DiMarco also helped protect Matt Ryan on pass plays.

Not to mention DiMarco evolved into a reliable pass-catching threat out of the backfield. Over the last two years, DiMarco caught 20 passes for 162 yards and three touchdowns.

Probably the most important factor of all is DiMarco's familiarity with the offense of former offensive coordinator Kyle Shanahan. Falcons coach Dan Quinn plans to keep the same principles from the scheme in place under new offensive coordinator Steve Sarkisian. Having DiMarco around to carry out the scheme would have made life easier on Sarkisian and the Falcons.

But obviously the Falcons weren't willing to pay DiMarco, who will sign a four-year, $8.5 million deal ($4 million guaranteed) with the Bills.

So what's next? Maybe the Falcons will raid Buffalo for a replacement with Jerome Felton out on the market. Felton, 30, was a Pro Bowler in 2012 with the Minnesota Vikings and started 12 games for the Bills the last two seasons.

Or maybe the Falcons will add a rookie fullback either late in the draft or among the undrafted players. However it all unfolds, the Falcons will miss DiMarco, at least immediately.