[1] With the retirement of Aaron Donald in March 2024, Havenstein is now the last remaining Rams player from the franchise's time in St. Louis that is still with the team.

At the end of the 2014 season he was named consensus 1st-Team All-Big Ten and 1st-Team All-American by the American Football Coaches Association.

[13][14] At the end of the season Havenstein was named to Pro Football Writers of America's All Rookie Team with Rams' teammate Todd Gurley.

[22] The Rams defeated the Dallas Cowboys in the Divisional Round and the New Orleans Saints in the NFC Championship Game to reach Super Bowl LIII, where they would lose to the New England Patriots by a score of 13–3.

[28] Havenstein won Super Bowl LVI when the Rams defeated the Cincinnati Bengals 23–20.

He started the other 14 games and the Rams' 24–23 Wild Card Round loss to the Detroit Lions.