The Astros will carry eight relief pitchers for the next week and will go with a four-man rotation. They won't need a fifth starter until Monday's doubleheader in Colorado, at which time a new rule will permit them to expand their roster to 26 players for one day.
Houston manager Brad Mills said that roster spot will be occupied by another starter. That could be Lyles, who wouldn't have to stay in the Minors for the usually required 10 days under that scenario. Mills said the rotation at Oklahoma City could be tweaked so Lyles would be in line to start one of the games Monday.
"Monday won't be his regular day to start, so we could adjust some things at the Minor Leagues in Oklahoma City to make that available, and we'll proceed with that," Mills said. "For us, [the 26th player] is probably going to be the starter for that game."