Louis Delmas returned to practice Tuesday. He could be available for Thanksgiving's game against the Texans. (US Presswire)

Detroit’s injury-depleted defense got a much-needed boost Tuesday when safety Louis Delmas and defensive tackle Corey Williams participated in the team’s only full workout before Thursday’s game against the Texans.

Williams missed Detroit’s losses to Green Bay and Minnesota after re-aggravating a previous knee injury in the Lions’ win over the Jaguars on Nov. 4.

Delmas, meanwhile, has not played since he re-injured his left knee during the Lions’ Week 8 win over the Seahawks. He has only appeared in three games this season, and his absence has clearly affected the defensive backfield’s pass coverage.

The Lions are notoriously cautious when it comes to resting injured players during the short turnaround week prior to the annual Thanksgiving Day game, so the fact that both players were able to practice Tuesday is a positive sign that they could be available against Houston.

LT Jeff Backus (hamstring) and CB Drayton Florence (concussion) did not participate in the portion of Tuesday’s practice that was open to media. Coach Jim Schwartz said Monday that it was doubtful Backus could recover from the injury he suffered Sunday against the Packers in time to play Thursday and extend his streak of 186 consecutive starts.

Florence finished Sunday’s game, but was diagnosed with a concussion Monday after reporting the onset of post-concussion symptoms. The fact that his concussion diagnosis was delayed means that the team will likely be very cautious before clearing him to return to action.

Cornerback Chris Houston (ankle) stretched before Tuesday’s practice, but did not participate in drills. He is expected to play Thursday.

WR Calvin Johnson (knee, thumb), DE Cliff Avril (back), DT Sammie Hill (knee), and CB Jacob Lacey (foot) all returned to practice Tuesday after being held out of Monday’s walk-through workout. All four players are expected to be available for Thursday’s game.

Follow Lions reporter John Kreger on Twitter at @CBSLions and @JohnKreger.