Gossett began the 2017 season with Nashville, and was promoted to Oakland on June 14 to make his major league debut that day against the Miami Marlins.[7] He pitched the remainder of the season with the A's, going 4–11 in 18 starts with an ERA of 6.11 in 91+1⁄3 innings. In 2018, he was limited to five starts and underwent Tommy John surgery on July 31.[8] He missed the remainder of the 2018 season and all of the 2019 season. On July 23, 2020, Gossett was designated for assignment.[9] He was released on July 27.
Boston Red Sox
On January 4, 2021, Gossett signed a minor league contract with the Red Sox organization.[10] In 20 appearances (18 starts) with the Triple-A Worcester Red Sox, he pitched to a 4.22 ERA and 7–5 record while striking out 81 batters in 98 innings.[6] He became a free agent following the season.
Minnesota Twins
On February 17, 2022, Gossett signed a minor league contract with the Minnesota Twins.[11] On August 19, 2022, he threw the first no-hitter in Wichita Wind Surge history, defeating the Tulsa Drillers 3-0. He elected free agency on November 10, 2022.