On Wednesday, the Astros promoted pitchers Jose Ciserno, Jarred Cosart and Jake Buchanan to Triple-A Oklahoma City from Double-A Corpus Christi and sent pitcher Paul Clemens to Corpus Christi from Oklahoma City.
"I've talked consistently about early August being a checkpoint for us, as far as our prospects' development," he said. "If we believe a prospect has done everything they need to do at that level and we want to challenge them a level ahead, we're going to go ahead and do that over the month of August. We'll be constrained by who's at what level, but there will be some moves."
Luhnow admitted there are some players performing at Triple-A Oklahoma City who deserve a shot to be evaluated at the Major League level in the same fashion some of the current Astros are getting. Any possible roster moves at the Major League level could be impacted by waivers, however.
Luhnow didn't give specific names, but the players on the roster who are currently out of options are pitchers Wesley Wright and Lucas Harrell and outfielders Brian Bogusevic and Jordan Schafer.
"It's one of the tough decisions we're going to need to make in the next week or two because there are some players that we can't move back to Triple-A without risking losing them," Luhnow said. "So you have to decide carefully how you do that. Not only that, but we have constraints here and positional requirements.
"In an ideal match, we would probably mix and match a bigger group and give everybody an opportunity up here to be evaluated in the last two months. There are realistic constraints that prevent us from doing that as much as we'd like to, but we're going to work around those."