NBC Sports reported that McDonald injured his ankle before Week 1 and Stewart had been recovering from a knee injury. McDonald was a second-round selection out of Ohio State in this year's draft. His addition brings another interior defender into the roster mix; the team has not announced a snap count or starting assignment for him.
Gronowski's and Oliver's stays on the active roster were brief. Houston's transaction record shows Gronowski was signed Wednesday and Oliver Thursday. Saturday's announcement closes those roster spots as the club prepares for its first divisional matchup of the season.
Houston and Tennessee enter the game at 0-4. The Texans' official preview identifies quarterback Cam Ward and a Tennessee offense averaging 261.3 yards per game through four weeks. Houston is trying to recover after allowing Dallas to win 34-30 last Sunday. The returning defenders give the coaches more available personnel for that effort, with Sunday's inactive list still needed to confirm who dresses.
Kickoff is scheduled for 1 p.m. Eastern on October 11 at Nissan Stadium. CBS carries the game regionally. McDonald and Stewart's activations are complete; Smith's absence is confirmed.