"As we get into the early part of July, we should have a really good idea of the likelihood of him being able to contribute," Mozeliak said. "Right now, all the steps he's taking, all the hurdles he's going over, it's positive. Really, it's about understanding what the trade market will look like with starting pitching, but also seeing if Chris Carpenter can help us.
"Right now we're able to have a pretty good idea of that. We still have a few weeks before we have to make a final decision on that. But again, I feel pretty optimistic with where we are on that given the uphill battle that it's been."
Carpenter's return would be a boost to a Cardinals rotation that is also currently without Jaime Garcia. While Garcia, who is resting a left shoulder strain, hasn't resumed throwing, Mozeliak said on Saturday that the lefty should "be cleared to take the next step soon."
Those impending additions would be critical for the Cards, who will also have to monitor the workloads of Lance Lynn and Adam Wainwright during the second half of the season.
Management was clear before the season started that Wainwright, who missed the 2011 season because of arm surgery, would likely not be allowed to clear the 200-innings mark this year. Lynn has never thrown more than 164 innings in any year, and that innings-high came two seasons ago.
Carpenter, Mozeliak confirmed, will come back as a starter. The club will not rush his return by starting him in the bullpen. Though the Cardinals were prepared to have Carpenter throw less than most starters in Spring Training, the club has not established a prescribed Minor League program for him this time around.
"Given it's Chris Carpenter, he's going to have a lot of say in this because he knows his body better than anybody," Mozeliak said. "You certainly don't want to leave him in the Minor Leagues if we don't have to."
As for the trade market now, it is still very much developing. More teams could fall into the buyer category, too, given the addition of one Wild Card team in both leagues.
"There does seem to be a balance in the standings right now," Mozeliak said. "How that will affect how teams look at if they're buyers or sellers, it's hard to say. But you get the feeling that, at the moment, there are more buyers than sellers."