Nelson was a defensive lineman for the Iowa Hawkeyes for five seasons, redshirting as a true freshman. Playing both defensive end and defensive tackle, Nelson finished his collegiate career with 111 tackles, 12 tackles for loss, nine sacks, nine pass break-ups, and one forced fumble.[3] Nelson was a four-time academic all-Big Ten Conference, and earned honorable mention all-Big Ten honors his senior season.
After going undrafted in 2019, Nelson was signed by the Detroit Lions as an undrafted free agent with the intention of moving him to the offensive line.[5] He was waived during final roster cuts, but was re-signed to the Lions practice squad and spent the rest of the season there as he adjusted to the offensive line. Nelson made the team out of training camp in 2020. Nelson made his NFL debut in the season opener on September 13, 2020, against the Chicago Bears.[6]
Nelson was given an exclusive-rights free agent tender by the Lions on March 4, 2021.[7] He signed the one-year contract on April 19.[8]
On March 14, 2023, the Lions re-signed Nelson.[9] He was placed on injured reserve on September 28 with an ankle injury.