Stills knelt during the national anthem, as he has for the past four seasons to protest racial inequality and police brutality.
After the Texans' 30-28 loss to the Saints, head coach Bill O'Brien spoke about Stills and his support for him.
"Kenny exercised his right and his prerogative. Not going to get into that. I talked to Kenny, Kenny is a good guy, very smart guy, very articulate guy, and he is a really good football player. Glad to have him here. He made some plays," O'Brien said.
As expected new #Texans receiver Kenny Stills took a knee during the national anthem.— Greg Bailey (@GregBailey13) September 9, 2019
Stills was acquired in a blockbuster trade from the Miami Dolphins with offensive tackle Laremy Tunsil.
Stills had 37 receptions for 553 yards and six touchdowns last season with the Dolphins. He made a name for himself during his tenure with the New Orleans Saints, who drafted him in 2013.
When it comes to protests during the national anthem, the Texans have not been very active, with players kneeling just once in a game two seasons ago following a comment about the demonstrations made by now-deceased team owner Bob McNair.
"My history here with the Houston Texans is I love the players, I have the players' back and we communicate about those things. I'm not going to really get into any discussions I would have with any player about those things, but I support the players in social justice initiatives," O'Brien said earlier this month after the trades.
In his debut with the Texans Monday night, Stills had three catches, including a 37-yard touchdown with under a minute remaining in the game.
The Associated Press contributed to this report.