The Houston Astros have decided not to keep right-hander Peter Lambert on their opening-day roster, despite his impressive performance in Grapefruit League play. Lambert, who has an opt-out in his minor-league deal, may remain in the team's system but may explore other options. Taylor Trammell was also among three players sent to the minors. The Astros have not yet announced their initial rotation beyond opening day starter Hunter Brown and Mike Burrows. The team plans to carry multiple long relievers initially in a five-man rotation before shifting to a six-man rot.