Matzek, 23, was originally selected by Colorado in the first round (11th overall) of the 2009 First-Year Player Draft out of Capistrano Valley High School in Mission Viejo, Calif. The 6-foot-3 lefty spent the entire 2013 season at Double-A Tulsa, where he was a member of the North Division All-Star Team. Matzek went 8-9 with a 3.79 ERA (142.1 ip, 60 er), 76 walks and 95 strikeouts in 26 starts for the Drillers. Matzek also competed in the 2013 Arizona Fall League for the Salt River Rafters, where he made 10 appearances, all in relief. He went 1-1 with a 3.86 ERA (11.2 ip, 5 er), 7 walks in 13 strikeouts during his AFL stint. Matzek was rated the Rockies 8th-best prospect by Baseball America prior to the 2013 season.
Sitton, 25, was originally selected by the Rockies in the seventh round of the 2010 First-Year Player Draft out of Oregon State University. The 6-foot-5 left-hander made 52 relief appearances for the High-A Modesto Nuts in the California League in 2013. He went 6-5 with a 2.93 ERA (67.2 ip, 22 er), 27 walks and 63 strikeouts for the Nuts last season. Sitton also participated in the 2013 Arizona Fall League, where he went 0-2 with a 8.00 ERA (9.0 ip, 8 er), 5 walks and 12 strikeouts.
Fernandez, 23, was originally signed by Colorado as a non-drafted free agent on November 13, 2007 out of the Dominican Republic. Fernandez spent the entire 2013 season at Single-A Asheville, making 35 relief appearances. In his 35 contests the 6-foot-2 right-hander went 2-2 with a 6.29 ERA (34.1 ip, 24 er), 11 walks and 55 strikeouts. Fernandez owned a 14.4 SO/9.0 IP ratio and a 5.00 SO/BB ratio with the Tourists in 2013. Fernandez was converted from catcher to pitcher prior to the 2009 season.
Herrera, 21, was originally signed by the Rockies as a non-drafted free agent on July 2, 2009 out of the Dominican Republic. The 6-foot-3 switch-hitting shortstop spent the 2013 season at Single-A Asheville where he was named the South Atlantic League's Most Valuable Player as well as the SAL Most Outstanding Major League Prospect by MiLB.com. Herrera was a Mid-Season and Post-Season All-Star in 2013, while also being named a Topps Class-A All-Star. In 126 games for the Tourists, Herrera hit .343 (162-for-472) with 33 doubles, 16 home runs, 76 RBI, 83 runs and 21 steals. Herrera ranked as the Rockies 12th-best prospect according to MiLB.com prior to the 2013 season.
Matthes, 26, was originally selected by Colorado in the fourth round of the 2009 First-Year Player Draft out of the University of Alabama. The 6-foot-2 right-handed hitter split the 2013 season between Double-A Tulsa and Triple-A Colorado Springs, playing in a 115 games total. Overall he hit .281 (121-for-431) with 30 doubles, 3 triples, 20 home runs, 63 RBI and 17 steals. He hit .297 (52-for-175) with 6 doubles, 11 home runs and 31 RBI in 47 games for the Sky Sox and .270 (69-for-256) with 24 doubles, 9 home runs and 32 RBI in 68 games for the Drillers. Matthes ranked as the Rockies 16th-best prospect prior to the 2013 season by Baseball America.
Parker, 24, was the Rockies first round selection in the 2010 First-Year Player Draft out of Clemson University. The 6-foot right-handed hitter spent the 2013 season at Double-A Tulsa, batting .288 (138-for-480) with 23 doubles, 23 home runs, 74 RBI and 70 runs scored. Parker was a Mid-Season and Post-Season Texas League All-Star in 2013. He also participated in the 2013 Arizona Fall League, where he hit .278 (27-for-97) with 9 doubles, 2 triples, 4 home runs and 18 RBI in 24 games. The former college quarterback was rated the Rockies 4th-best prospect prior to the 2013 by Baseball America.
The Rockies have 39 players on the 40-man roster.