[6] Nevin made his professional debut that year with the Grand Junction Rockies[7] and spent the whole season there, batting .265 with two home runs and 18 RBI in 53 games.

[8] He began 2017 back with Boise, and after six games, was promoted to the Asheville Tourists[9] where he finished the year batting .299/.353/.454 with eight home runs, 52 RBI, and ten stolen bases.

[11] After the season, he played for the Salt River Rafters of the Arizona Fall League[12] where he won the AFL batting title and finished second in MVP voting.

[15] On August 30, 2020, the Rockies traded Nevin, Terrin Vavra and a player to be named later to the Baltimore Orioles in exchange for Mychal Givens.

On May 28, 2021, Nevin was promoted to the major leagues for the first time, and was announced as the starting first baseman in that day's game against the Chicago White Sox.

In the game, he notched his first MLB hit, a ground rule double off of White Sox starter Dallas Keuchel.

[19] On October 3, 2021, in the final game of the year, Nevin hit his first major league home run off of Toronto Blue Jays starter Hyun-jin Ryu.

[26] Despite a strong spring training in which he hit .333 across 23 games, Nevin did not make the Opening Day roster and was designated for assignment on March 28.