Steve Young expects Matt Ryan to use his arsenal of weapons to get Atlanta's offense back on track. (0:42)

Atlanta Falcons running back Devonta Freeman is expected to be sidelined for two to three weeks with a right knee contusion, according to a source.

The Falcons, who already had ruled out Freeman for Sunday's NFC South matchup with the Carolina Panthers, are confident he won't miss more than the two or three games, although another source said the running back could miss three to four weeks.

One reason Atlanta is confident Freeman's return will be sooner rather than later is because he already is going hard at rehab, trying to make progress. But his absence will extend to multiple games -- it's now just a question of how many.

With Freeman out, the Falcons will start Tevin Coleman on Sunday and use fourth-round pick Ito Smith as his backup. It's a big opportunity for Coleman, who is scheduled to become a free agent after this season. Coleman's career rushing numbers against the Panthers include 36 carries for 152 yards with a touchdown, six first downs and a long run of 55 yards.

Freeman suffered the injury in the 18-12 season-opening loss at Philadelphia. The two-time Pro Bowler said after the game he was fine but did not practice all week.

Coach Dan Quinn said earlier this week that the injured knee is the same one that Freeman hurt last season, but there is no structural damage.

Freeman, a two-time Pro Bowler, rushed for 865 yards and seven touchdowns on 196 carries in 2017. He had back-to-back, 1,000-rushing-yard seasons in 2015 and '16. Last year, a significant right knee injury limited Freeman's production.

Information from ESPN's Vaughn McClure was used in this report.