Stewart had four total tackles and recovered a fumble in Sunday's win over Chicago.
The Colts agreed to re-sign Stewart on Tuesday to a three-year, $39 million deal, Adam Schefter of ESPN reports.
Stewart racked up 41 tackles (23 solo) and 0.5 sacks across 11 regular-season games with the Colts in 2023.
The NFL suspended Stewart six games for violating the league's PEDs policy, Ben Arthur of FoxSports.com reports.
Stewart had five total tackles and a tackle for loss in Sunday's loss to Jacksonville.
Stewart recorded seven tackles (six solo) and a pass defended in Sunday's 17-16 defeat against the Commanders.
Stewart tallied 12 tackles (seven solo) during a 19-10 loss to the Titans on Sunday.
Stewart recorded five tackles (four solo) and one sack during Sunday's 34-27 win over the Jaguars.
Stewart had five total tackles, a QB hit and two tackles for a loss in Sunday's tie at Houston.