Embattled Miami Dolphins guard Richie Incognito believed he was friends with teammate Jonathan Martin and feels "shocked" and "betrayed" by Martin's claims of harassment, a source with knowledge of the situation told ESPN.com on Friday night. Incognito was suspended indefinitely last Sunday for conduct detrimental to the team after Martin presented evidence -- including threatening voice mails and text messages -- to the Dolphins, the NFL and the NFL Players Association. The Dolphins are currently under investigation by the NFL, while both Martin and Incognito are away from the team. "It's probably a combination of totally blindsided and a bit betrayed," the source said of Incognito's current state. "He's shocked. He can't believe this happened and thinks it probably could have been avoided." According to the source, Incognito viewed himself as a "tough-love older brother" to Martin. Incognito gave Martin a hard time but also was protective of the second-year player, the source said. Multiple sources confirmed to ESPN on Monday that Incognito used racial epithets and profane language toward Martin on multiple occasions. In a transcript of a voice mail message from April, Incognito referred to Martin as a "half n----- piece of s---," and added, "F--- you, you're still a rookie. I'll kill you." Incognito received overwhelming support in Miami's locker room following the suspension. The reception toward Martin, meanwhile, was lukewarm. Some Dolphins veterans even expressed dislike for the way Martin handled the situation.