Buckner, who is not related to former Red Sox first baseman Bill Buckner, was in the Rockies' system in Triple-A last year. He was 4-8 with an ERA of 6.03 in 21 starts. Buckner threw 80 strikeouts and 52 walks in 23 appearances. In 36 MLB appearances (21 starts), Buckner is 6-11 with a 6.25 ERA.
Mock was 4-13 in three years with the Washington Nationals, making a total of 55 appearances. His ERA was 5.17 with the Nationals and he struck out 8 batters per nine innings. In the minors last season, Mock was 1-5 with a 6.39 ERA. He had 51 strikeouts and 29 walks in 49 1/3 innings pitched.
Buckner is expected to compete for a starting job in the Red Sox system while Mock will compete for a spot as a reliever in the Red Sox system.