Houston signed free agent wide receiver Devin Lucien and cornerback Josh Thornton to the practice squad and signed wide receiver DeAndrew White and tight end MyCole Pruitt in corresponding transactions. The moves were announced on Tuesday.
Pruitt, 25, was a fifth round pick by the Minnesota Vikings in the 2015 NFL Draft. He had 89 yards on 10 receptions during his rookie campaign for the Vikings, making three starts. Pruitt appeared in four games for the Chicago Bears and Vikings during the 2016 season.
White, 26, appeared in four games in 2015 for the San Francisco 49ers.
Fiedorowicz suffered a concussion in Sunday's loss to the Tennessee Titans. He also missed eight games earlier in the season from suffering a concussion. Fiedorowicz had 14 catches for 127 yards in five games this season. He signed three-year, $21.5 million contract with the Texans in August. The 26-year-old tight end suffered another concussion last season.
Ellington also suffered an injury in Week 13, leaving Sunday's contest with a hamstring ailment. He had 330 yards and two scores on 29 catches this season for the Texans.
The Texans face the San Francisco 49ers at 1 p.m. Sunday at NRG Stadium.