Barnhart, 31, has played his entire career in the Reds organization. A 10th-round pick in 2009, he made his big-league debut in 2014 and won two Gold Glove awards in eight seasons.
Quintana, 24, was a second-round pick by the Tigers in 2019. In two seasons in the minors, he has .190 with 11 home runs. He played 82 games for Single-A Lakeland last season.