Mike Treier is in his third season with the Giants and his second as the team's assistant defensive backs coach. He assists Jerome Henderson in coaching the secondary. In Treier's debut season with the Giants in 2020, he was the team's defensive quality control coach, his first NFL position.
In 2021, the Giants' pass defense ranked 15th in the NFL, allowing 225.8 yards a game. Second-year pro Xavier McKinney led the team with five interceptions, the highest total by an NFL safety last season. McKinney earned NFC Defensive Player of the Week honors after recording his second game of the season with multiple interceptions vs. Las Vegas on Nov. 2, when he twice picked off Raiders quarterback Derek Carr. McKinney returned the second interception 41 yards for a touchdown at the beginning of the third quarter. Julian Love continued to be the secondary's most versatile player and cornerback Adoree' Jackson had 62 tackles and eight passes defensed despite missing three games.
The defensive staff coached one of the NFL's most improved units in 2020. The defense ranked ninth in the league by allowing 357 points, 94 fewer than their total in 2019. The Giants were 12th in the league by allowing 349.3 yards-per-game after finishing 27th at 377.3 yards the previous season. Giants opponents averaged just 5.3 yards a play, the NFL's ninth-lowest figure.
Treier joined the Giants from Marshall University, where he coached from 2017-19 in his second stint with the school.
In 2019, Treier was the safeties coach and recruiting coordinator for a Thundering Herd team that finished 8-5, including 6-2 in Conference USA. In addition to his duties as safeties coach and recruiting coordinator, Treier was also heavily involved in Marshall's special teams, especially in the punt game where the Herd excelled during Treier's entire tenure.
Treier spent a second season as Marshall's cornerbacks coach in 2018, when the Herd was 9-4 overall and 6-2 in the conference and finished third in the league by allowing only 21.8 points a game. Marshall tied for fifth in the conference with 12 interceptions. Cornerback Chris Jackson was named second-team All-Conference USA and Steven Gilmore was selected to the league's all-freshman team.
Treier returned to Marshall as the cornerbacks coach in 2017. Jackson, then a sophomore, was chosen honorable mention all-conference after leading the team with three interceptions.
In 2016, Treier was named the secondary coach at UT-Martin. By the end of that season, he had been promoted to the SkyHawks' defensive coordinator position.
Treier first coached at Marshall in 2013-15, when he was a graduate assistant.
Treier was raised in Lancaster, Pa. and attend Penn Manor High School in Millersville, Pa. He has a bachelor's degree in business management from Temple University.
2011-2012 Temple University defensive student assistant
2013-15 Marshall University graduate assistant
2016 University of Tennessee at Martin secondary/co-defensive coordinator
2017-18 Marshall University cornerbacks/recruiting coordinator
2019 Marshall University safeties/recruiting coordinator
2020 New York Giants defensive quality control
2021-22 New York Giants assistant defensive backs