Lyles, 23, has pitched for the Astros in each of the last three seasons, with a 14-29 record with a 5.35 ERA (377.0 ip, 224 er), 117 walks and 259 strikeouts in 72 games, 65 starts.
In 2013, the righthander went 7-9 with a 5.59 ERA (141.2 ip, 88 er), 49 walks and 93 strikeouts in 27 games, 25 starts.
Lyles, who made his Major League debut as a 20-year-old on May 31, 2011 at the Chicago Cubs, owns a career 62.0-percent ground ball percentage. A native of Florence, SC, Lyles was originally selected by Houston in the supplemental first round (38th overall) of the 2008 First-Year Player Draft out of Hartsville High School in Hartsville, SC. The 6-foot-4, 215-poung righthander was named the Astros top prospect by Baseball America prior to the 2011 season.
Barnes, 27, spent the entire 2013 season in Houston as one of the club’s regular outfielders. He hit .240 (98-for-408) with 17 doubles, 1 triple, 8 home runs, 41 RBI, 46 runs and 11 steals in 136 games. The 6-foot-2 right-handed batter is a career .233 (118-for-506) hitter in 179 career Major League games with the Astros (2012-13). A versatile outfielder, Barnes has played each of the three outfield positions in each of his first two campaigns, although he has spent the majority of his time in center field (148 games). Barnes was originally selected by Houston in the sixth round of the 2005 First-Year Player Draft out of Cypress Junior College (Calif.).
Fowler, 27, played in 119 games for the Rockies last season and batted .263 (109-for-415) with 18 doubles, 3 triples, 12 home runs, 42 RBI and 71 runs. Over his six-year Major League career, all with Colorado, Fowler has hit .270 (606-for-2248) with 120 doubles, 53 triples, 40 home runs, 210 RBI and 376 runs in 667 games. Fowler was originally selected by Colorado in the 14th round of the 2004 First-Year Player Draft out of Milton High School (Ga.).
The Rockies now have 38 players on the 40-man roster.