Newton, 30, is a former seventh-round pick of the Texans back in 2011. He was entering the third year of his five-year, $26.5 million contract that includes $10 million guaranteed and set to make a base salary of $2.25 million for the 2017 season when the Texans released him.
The Saints signed him to a contract last week.
In 2016, Newton appeared in six games for the Texans and was rated by Pro Football Focus as the No. 47 offensive tackle out of 78 qualifying players.