Ogbonnaya spent the last two-plus seasons with the Cleveland Browns, rushing for 240 yards on 49 carries last season. He was released by Cleveland, who listed him as a fullback, in the team's final round of roster cuts at the end of the 2014 preseason.
The 28-year-old was originally a seventh-round pick of the St. Louis Rams in 2009 out of Texas. His career-best rushing total came in 2011, when he ran for 340 yards on 76 carries for the Browns and Houston Texans.
The Panthers were in need of help at running back after injuries to their top two backs.
DeAngelo Williams is reportedly "week-to-week" after injuring his ankle in Carolina's loss to the Baltimore Ravens on Sunday. Williams is unlikely to play this Sunday in the Panthers' game against the Chicago Bears.
Starting fullback Mike Tolbert was placed last week on injured reserve/designated to return with a hairline fracture in his leg.
With the aforementioned injuries, undrafted rookie Darrin Reaves is now the team's top running back. Reaves had 12 carries for 26 yards against the Ravens.
To make room for Ogbannaya on the roster, the team waived rookie back Tauren Poole. Carolina had signed him to the practice squad and then the active roster last week, but Poole fumbled in his lone carry against Baltimore.
Carolina is 2-2 this season. The Bears, the Panthers' Week 5 opponent, are also 2-2.
- Ben Estes