Ben Volin of the Boston Globe broke down what it means for New England and Shelton:
The big tackle in the Super Bowl came against Los Angeles Rams running back C.J. Anderson when Shelton swam through the line and stopped his opponent in the backfield for a three-yard loss. The tackle earned him the league's Way to Play award for the week.
Shelton appeared in 13 regular-season games and two playoff games last season after being traded from the Cleveland Browns in the previous offseason.
Meanwhile, the run defense was a key part of the Patriots' success in Super Bowl LIII as the Rams were held to just 62 rushing yards on 18 attempts.
Re-signing Shelton allows for some continuity on the defensive line with Trey Flowers, Malcom Butler and Adrian Clayborn leaving in free agency.
The 25-year-old also has plenty of upside as a former first-round pick from the 2015 draft. He started 44 games in his first three years with the Browns and still made an impact in 2018 even with a smaller role with the Patriots.
With more playing time, Shelton has a chance to have an even bigger showing in 2019.