The league is investigating the circumstances of an incident in which offensive lineman Jonathan Martin left the team last week because of "emotional issues." Dolphins lineman Richie Incognito was suspended indefinitely Sunday by Coach Joe Philbin for his treatment of Martin.
ESPN, citing multiple unnamed sources, reported Tuesday that Incognito, who is white, used racial slurs and foul language toward the biracial Martin several times -- including a voice mail message in April in which Incognito called Martin a "half n----- piece of s---."
Sources told the broadcaster Martin was the recipient of text messages from Incognito that impugned his sexuality.
A statement issued by the NFLPA said the union expects "a safe and professional workplace" for players.
"As the representative organization of all players, the NFLPA will insist on a fair investigation for all involved. We will continue to remain in contact with the impacted players, their representatives and player leadership," the statement said.