His third year for Big Blue would see Armstead given some starting time at LB. Getting the first team nod for two contests, Armstead put up 36 solo tackles, 10 assists, half a sack, a forced fumble and an interception for a touchdown.
It was in Armstead's fourth season for New York that he had his breakthrough and became a full-time starter. For the 1996 NFL regular season, Armstead made a hefty 83 solo tackles with 31 assists, three sacks, two interceptions, a forced fumble and two fumble recoveries. He was now part of the Giants' starting defensive corps and earning his stripes.
1997 would see Armstead receive an invitation to the Pro Bowl and be named an All-Pro. He garnered those honors on the back of a regular season which saw him pick up 101 solo tackles, 31 assists, 3.5 sacks and two interceptions, one of which would be for a touchdown.
Armstead would, in fact, be invited to five consecutive Pro Bowls, showing his consistency as a member of the Giants linebacker crew. He would contribute significantly to the team's run to Super Bowl XXXV against the Baltimore Ravens, notching 1.5 sacks in those playoffs. In total, for his New York Giant career, the former Miami Hurricane put up the following regular season numbers: 594 solo tackles, 183 assists, 30.5 sacks, 12 interceptions and 11 forced fumbles.