Sherriff, whose maternal grandparents were Holocaust survivors, was drafted by the St. Louis Cardinals in 2011. Originally a starting pitcher, the left-hander transitioned to a reliever during 2014 spring training. Pitching for Triple-A Memphis, he was named a Pacific Coast League All-Star in 2016 and 2017. The Cardinals called him up on August 23, 2017, and two days later he pitched three scoreless innings in his major-league debut against Tampa Bay. A series of injuries limited his playing time in 2018 before he underwent Tommy John surgery in June. In 18 games through 2018, he had a combined 2-1 record with a 4.05 ERA. Ryan also pitched for Team Israel in the 2017 World Baseball Classic qualifying round.