The 5-foot-9, 209-pound Slaton was a third-round pick in 2008 and was the NFL's top rookie rusher with 1,282 yards. He rushed for 437 yards but fumbled seven times in 2009 and was placed on injured reserve after 11 games. He had neck surgery after the season, and never regained his form.
Arian Foster emerged in 2010, and Slaton was relegated to backup duty and returning kicks. Foster has been limited by a left hamstring strain early this season, and 2010 second-round pick Ben Tate topped 100 yards rushing in Houston's first two games. Slaton has only seven carries for 20 yards this season.
Houston coach Gary Kubiak said Monday that he's optimistic that Foster will be ready when Houston (2-1) plays Pittsburgh (2-1) on Sunday.
Foster, the NFL's leading rusher last season, has been inactive for two of Houston's first three games.
"I hope he's full-go," Kubiak said. "I know he's champing at the bit to get back on the field full-time and we'll sit there and watch how he works and hopefully everything's full speed."
The 6-foot, 220-pound Ogbonnaya was the Texans' leading rusher in the preseason and the only running back who avoided an injury during training camp. A former Texas star, Ogbonnaya was a seventh-round draft pick by St. Louis in 2009, then was cut last September.