Ninkovich has been away from the team for personal reasons and speculation has been circulating that he could be walking away from the game.
New England has a news conference for 12:15 p.m. ET Sunday.
Ninkovich, 33, is a former sixth-round pick of the Saints back in 2006. He later played for the Dolphins before returning to New Orleans in 2008 and eventually ending up with the Patriots the following year.
Ninkovich is currently in the final year of his contract and was set to make a base salary of $1.5 million for the 2017 season.
For his career, Ninkovich appeared in 131 games and recorded 282 tackles, 46 sacks, 12 forced fumbles, 14 recoveries, five interceptions, 18 pass defenses and scored two defensive touchdowns over the course of 11 seasons.