Lancaster redshirted his first year at Northwestern, during which he switched positions from the offensive line to defensive tackle.[2] He became a three-year starter for the Wildcats, starting the last 39 games of his career, and accumulated 101 total tackles, 18.5 tackles for loss and 3.5 sacks.[3] As a senior, Lancaster was named a team captain and set career highs in 40 tackles, 9.5 tackles for loss, and 2 sacks and was named honorable mention All-Big Ten.[4]
Lancaster signed with the Green Bay Packers as an undrafted free agent on April 28, 2018.[6] He was cut by the Packers at the end of training camp and then subsequently re-signed to the team's practice squad.[7] Lancaster was signed to the Packers' active roster on October 6, 2018, and made his NFL debut the following day in a 31–23 loss to the Detroit Lions, appearing on special teams.[8][9] Lancaster made his first career start on November 25, 2018, recording one tackle in a 24–17 loss to the Minnesota Vikings. In his rookie season, Lancaster appeared in 12 games (5 starts) and made 25 tackles, including one for loss.[10]
In week 8 of the 2019 season against the Kansas City Chiefs, Lancaster forced a fumble on running backLeSean McCoy and recovered the ball in the 31–24 win.[11] In 2019 he played in all 16 games with 10 starts for the Packers during the regular season and recorded 30 tackles, 1.5 sacks, a forced fumble and a fumble recovery and started both of the team's playoff games.[12] On April 25, 2020, the Packers re-signed Lancaster to a one-year contract as an exclusive-rights free agent.[13][14]
Lancaster re-signed with the Packers on March 30, 2021.[15] He was placed on the reserve/COVID-19 list on September 28, 2021.[16] He was activated on October 9, 2021.[17]
Las Vegas Raiders
Lancaster signed as free agent with the Las Vegas Raiders on May 25, 2022.[18] On August 28, 2022, Lancaster was placed on injured reserve.[19] He was released on September 5, 2022.[20]
Denver Broncos
On May 23, 2023, Lancaster signed with the Denver Broncos.[21] He was released on August 29, 2023 and re-signed to the practice squad.[22][23] He was not signed to a reserve/future contract and thus became a free agent at the end of the season.[24]