Foster suffered a hamstring injury against the Kansas City Chiefs two weeks ago. He did not finish the game, leaving the Texans with only one active running back in Tate.
Tate later suffered four broken ribs but managed to finish the game. He practiced on a limited basis Wednesday and Thursday.
Of Foster, Kubiak said: "He got better today. He practiced better today than he did yesterday."
Foster is officially listed as questionable on the club's injury report.
The Texans weren't sure which running back would be behind Foster. Houston signed three to the active roster this week -- rookies Dennis Johnson and Ray Graham and young veteran Deji Karim, all of whom were in training camp with the Texans.