Halton (ankle) was unavailable for practice Sunday, Matt Maiocco of NBC Sports Bay Area reports.
Halton is dealing with an apparent ankle injury, and as a result, he spent the first practice of the week on the sidelines. The defensive lineman recorded four total tackles (two solo), one of which was for a loss, in the team's 19-13 loss to the Titans in their preseason opener. He will now have a couple more chances to return to practice ahead of Thursday's preseason matchup with the Chargers.