The Texans signed veteran TE Derek Fine, FB Justin Griffith and WR Bobby Williams on Wednesday.
Griffith, 29, started 11 games for Seattle last season, catching 19 passes for 118 yards and a touchdown. He tried out for the Texans at the club's most recent minicamp, as did Williams, 24, who spent last preseason with Minnesota.
Fine, 26, started six games for Buffalo in 2009, catching nine passes for 64 yards and no touchdowns.
Also, the Texans released seven players on Wednesday. Undrafted rookies FB Jack Corcoran, WR London Crawford, OG Kristian Matte, LB Will Patterson, QB Tyler Sheehan and OT Adam Ulatoski were waived, as was veteran TE Michael Gaines.