Brantley (shoulder) was assigned to Triple-A Sugar Land to start a rehab assignment Tuesday.
The 36-year-old will be in the lineup for the Space Cowboys on Tuesday, marking the start of his second rehab assignment of the season. Brantley was shut down in early May after a nine-game rehab stint due to inflammation in his surgically repaired right shoulder, and he'll likely require at least a handful of games in the minors before the Astros activate him from the injured list for his season debut.