Martin, a tackle, remained absent from practice Monday one week after he suddenly left the team because of emotional issues. Also missing was Incognito, a guard suspended indefinitely late Sunday by coach Joe Philbin for his treatment of Martin.
The 319-pound Incognito, a ninth-year pro, is white. The 312-pound Martin, who is in his second NFL season, is black. For much of the season they've played side by side.
The team and NFL continued their investigation into allegations by Martin's representatives that he was bullied, and Philbin said Dolphins owner Stephen Ross asked league commissioner Roger Goodell for assistance. The NFL Players Association also planned to look into the matter.
It's unclear whether coaches or management had any inkling of harassment between the players before Martin left the team, and Philbin declined to answer a question about the locker-room culture. Recent rumblings of dissension have also included complaints by young players that they're pressured to pay more than their share when team members socialize together.
Around the league
Broncos • Denver appointed defensive coordinator Jack Del Rio as interim coach in place of John Fox, who underwent heart surgery Monday in Charlotte, N.C.
Niners • Receiver Mario Manningham is back for San Francisco, activated from the physically unable to perform list and available for Sunday's home game against Carolina. Manningham injured his left knee in a loss at Seattle on Dec. 23.
Bills • Buffalo released quarterback Matt Flynn in an indication rookie starter EJ Manuel (sprained knee) is ready to return from injury.
Bengals • Cincinnati put All-Pro defensive tackle Geno Atkins (knee) on the injured reserve list Monday.