Martin left the Dolphins in late October and later claimed to have been mistreated by teammates. When insulting messages from Incognito to Martin were disclosed, Miami suspended Incognito.
Martin's agent Kenny Zimmerman, another target of insults from Incognito, was accused by Incognito of giving ESPN a voice mail message in which Incognito is heard using offensive language.
Wednesday, Incognito sent off a series of Twitter posts in response, one of which starts: "Dear Jon Martin..... The truth is going to bury you and your entire 'camp.' You could have told the truth the entire time."
Incognito said he himself was "guilty of being a loyal friend and good teammate." He also apologized "for my poor language and rude remarks."
The Martin incident is the center of an independent report on the workplace environment at the Miami Dolphins. The report is expected this week.