The message was in tribute to Eric Garner, a Staten Island man who died after being placed in a chokehold by police in July. Garner was heard on video saying "I can't breathe" while in the chokehold.
Bush and Bademosi wore the message on their shirts during warm-ups.
Joseph wrote the words on his cleats and tweeted out a photo on Sunday ahead of the Rams' game against the Washington Redskins.
On Saturday, Chicago Bulls guard Derrick Rose wore a shirt that read "I Can't Breathe" during warm-ups.
The tributes come one week after five Rams players used the "Hands Up, Don't Shoot" gesture before last Sunday's game. The gesture has been used by protestors in Ferguson, Mo., and across the country in the wake of the shooting death of 18-year-old Michael Brown.
ESPN's Adam Schefter reported that an NFL executive said he wouldn't be surprised if there are more players who use the "Hands Up, Don’t Shoot" message at Sunday's games.
- Molly Geary