Jace Mercer is a rookie with the ThunderBolts in 2021. He signed as a free agent on August 13, 2021 after playing five years at the Univeristy of Cincinnati. He hit a career-high .340 as a senior in the spring of '21 with a .985 OPS and 22 stolen bases. He also clubbed nine homers after hitting five in his first four years. His efforts netted him Second Team All-American Athletic Conference and Second Team All-East Region honors. He was also named one of three finalists for the best defensive second baseman in the nation.

In his career at Cincinnati, Jace was a .285 hitter with a .394 on-base percentage. He stole 20 or more bases twice and finished his career with 61 steals. In 200 career games, he drove in 102 runs and in 2019, helped the team to American Athletic Conference Tournament championship. Prior to Cincinnati, he attended Johns Creek High School in Johns Creek, Georgia.