He has started 27 games for the Saints, recording 218 tackles, four sacks and three interceptions. He made 10 tackles and a sack in 16 games last season, but some of his biggest plays came on special teams.
Robertson recovered a blocked punt against Atlanta and also made stops on a fake field goal and a fake punt play in 2018.
The former North Texas player was originally signed to the Cleveland Browns’ practice squad near the end of the 2011 season.
The Saints didn’t release contract terms.