It's a position that's unsexy but significant—especially for a team that must cover for its quarterback with a remedial passing game and a heavy emphasis on running the ball. Left guard Xavier Su'a-Filo, whom the Texans infamously selected at the top of the second round ahead of quarterback Derek Carr in 2014, hasn't worked out. The 6' 4", 320-pound Su'a-Filo can get into his pull-blocks well (he stays tight to the other blockers as he moves behind them), but landing those blocks is a different story. He is neither nimble nor powerful, and he almost certainly won't be re-signed when his rookie deal expires after 2017 because he's also erratic in pass protection. And so is right guard Jeff Allen.