Bourgeois spent most of the season with the Reds and would have been eligible for salary arbitration this winter. After missing the beginning of the season with a fractured left scapula, he was called up from Triple-A Louisville on June 28 and batted .240 with three home runs and 14 RBIs in 68 games.
Boesch opened the season with the Reds after he earned a spot in camp but did not fare well at the plate before being optioned to Louisville on June 15. He returned in August and batted .146 with one homer and three RBIs over his 51 big league games overall.
Negron also made the big league roster out of Spring Training, but he struggled during his opportunities. While making 20 starts at seven different positions, he batted .140 in 43 games and was optioned to Louisville on June 25. In his first game back with the club on Sept. 8, he suffered a torn labrum and fractured scapula in his left shoulder trying to make a diving catch in left field.
Adcock was 1-2 with a 6.00 ERA in 13 big league games this season but did not pitch after July 26 because of a torn ulnar collateral ligament in his right elbow that required Tommy John surgery.
Balester was acquired from the Pirates in exchange for cash on June 17 and promoted to the Majors from Triple-A Louisville on Aug. 23. He was 1-1 with a 7.47 ERA in his 15 appearances for Cincinnati.
Smith was one of nine rookies to make a start for the Reds this season after his promotion from Double-A Pensacola. Over his multiple callups, he was 0-4 with a 6.89 ERA in nine games, including seven starts, in the Majors.
Holmberg spent the bulk of 2015 with Louisville, but was 1-4 with a 7.62 ERA in six big league starts.
Mark Sheldon is a reporter for MLB.com. Read his blog, Mark My Word, follow him on Twitter @m_sheldon and Facebook and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.