Incognito was being reviewed by the Dolphins, the NFL and the NFL Players Association for harassment of teammate Jonathan Martin, who left the team last week after a lunchroom incident.
The Dolphins announced in a statement late Sunday that Incognito had been suspended, adding "we believe in maintaining a culture of respect for one another and as a result we believe this decision is in the best interest of the organization at this time. As we noted earlier, we reached out to the NFL to conduct an objective and thorough review. We will continue to work with the league on this matter."
Sources told ESPN that one of the significant allegations being reviewed is that Incognito got Martin to contribute $15,000 to help finance a trip to Las Vegas by some teammates last summer, even though Martin preferred not to travel with the group.
Rather than go, Martin simply gave Incognito the $15,000, sources told ESPN, fearing the consequences if he did not hand over the money.
One source said there are other instances of intimidation captured in text messages and at least one demeaning voice mail. In addition, some of the messages were racially charged in nature, according to ESPN and media reports. The alleged racial aspect of the communication was first reported by Fox Sports. Also, Martin's recent reported text communications with Incognito that indicated he did not hold the guard responsible for his absence were sent out of fear of retribution, sources told ESPN.
Incognito, who has been a part of the Dolphins' six-player leadership council, started all eight games for the Dolphins (4-4). He will be an unrestricted free agent after the season. Backup guard Nate Garner will start in his place.
Representatives for Martin contacted the team Sunday regarding allegations of harassment and player misconduct, with the Dolphins saying in a statement they have asked the NFL to review the matter.
Incognito took to Twitter earlier Sunday, saying that he wants his "name cleared." He called the reports "false speculation" and "slander" and said ESPN was hiding behind sources "who are not man enough to put their name behind the BS you report."
— Richie incognito (@68INCOGNITO) November 3, 2013
This is not the first time Incognito has been in trouble. In 2009 he got into a verbal altercation with then-St. Louis Rams coach Steve Spagnuolo for multiple penalties in a game. Incognito was waived a few days later. Incognito also was suspended for the 2004 season in college at Nebraska because of off-the-field incidents.
Incognito was voted the second-dirtiest player in the NFL from a player poll in the Sporting News during the 2012 season. Houston Texans defensive lineman Antonio Smith also swung a helmet at Incognito during an August preseason game, alleging foul play.
Incognito talked to NFL.com last summer about problems he's had to overcome through therapy with anger-management issues and substance abuse, particularly when he was with the Rams at the beginning of his career.
"I mean, we'd have practice the next morning, and I'm out until all hours of the night, running the town," Incognito told NFL.com. "Drinking. Doing drugs. I was doing everything that a professional athlete should not be doing."
He had seemed to turn his image around with the Dolphins, however, earning a share of the team's "good guy" award last season, which is given to the player who is most cooperative with the local media. He also was voted to his first Pro Bowl in 2012.
"I'm definitely not a choir boy," Incognito told NFL.com in the story published earlier this year. "You know, I'm definitely not healed, and I'm not saying that I don't make mistakes. But from where I was to where I am now, I mean, it's night and day. And it's something that, you know, I hope people can respect about me."
The Dolphins will return to the practice field Monday, minus Incognito, to prepare for their "Monday Night Football" game against the Tampa Bay Buccaneers next week.
It is unknown whether and when Martin plans to return to the team. The Dolphins have until 4 p.m. ET Tuesday to take him off the non-football-related illness list.
ESPN's Chris Mortensen and Adam Schefter contributed to this report.