IIRC, CND, Foster was really gimpy the first 3 or 4 weeks of last season. Which included the Dolphins game during Week 2. I remember it because I had drafted Tate in a FFL because of Foster's hammy issues he had suffered off and on throughout camp and even the preseason games that led up to the 2011 Reg Season. I figured I could get Tate's production for the first several games, and I did. After Foster came back, though, Tate's numbers regressed immediately.
In fact, Foster's hamstring was acting up as early as JULY 18th according to a Bleacher Report rumor article, specifically the speculation that it would have a tendency to linger if not treated properly. Link to article HERE
In this NBC Sports article, Foster had aggravated the left hamstring in a preseason game. The hammy cost him half of August. Link HERE
He had only 10 carries for 33 yards in Week 2 of the reg season vs. Dolphins, sitting out the entire 2nd half. The hamstring was still a major problem because he was sidelined completely the next week vs. the Saints. Link HERE
So what we learned from that is this: Foster was effectively invisible for July, August, and the first month of the 2011 reg season...Tate misses 3 games in a 4-week stretch (Bills, Bye week, Jags, Lions)...and Kubiak is unhappy with Tate for essentially the same thing Foster dealt with on a much longer timeframe in 2011.
All signs point toward Tate and his agent making it clear that Tate really should be getting a chance to start (somewhere) and that he's basically biding his time here in Houston. If I were the Texans, I would seek a trading partner in the offseason and get some draft day collateral out of him/ Otherwise, he's going to be gimpy and a bit unreliable in 2013 in his last year here. Get something before he goes on his own, that's my take on it.