[5][6] He started all 15 games, including the 2015 College Football Playoff National Championship victory over Oregon.

[12] Decker started all 16 games at the left tackle position in his rookie season and was the only player besides quarterback Matthew Stafford to play every snap on offense for the Lions.

[13] Decker was named the Lions Rookie of the Year for 2016 in voting by the Detroit Sports Broadcasters Association.

[15] He was activated off PUP on November 11, 2017,[16] and started the final eight games of the season at left tackle.

On December 3, 2018, Decker was put in contact with the fan that caught it and got his first ever touchdown ball back.

[20] On September 1, 2020, Decker signed a five-year, $70.35 million contract extension with the Lions.

[25] On January 2, 2022, in a game against the Seattle Seahawks, Decker scored his second career touchdown on a pass from Tim Boyle.