Mozeliak has made moves for relievers before. Last season, the Cardinals acquired Steve Cishek from Miami for Kyle Barraclough, and the club traded for Marc Rzepczynski and Octavio Dotel near the Deadline in 2011.
The decision to seek bullpen help comes even as the Cardinals have three everyday position players on the disabled list in Brandon Moss, Matt Carpenter and Jhonny Peralta. Mozeliak remains confident that their eventual return means he won't need another bat.
"I've never been focused on the position-player side of that market, anyway," Mozeliak said. "Arguably, if I didn't think this was a problem that would have some resolution, I might have to think about it differently from that standpoint."
The Cardinals' bullpen owns a 5.06 ERA since the All-Star break, entering play Wednesday, and Trevor Rosenthal leaving the closer role in late June has caused problems. Rosenthal pitched a scoreless inning with two strikeouts in the ninth on Monday night, but his ERA still stands at 8.31 since the beginning of July. Jonathan Broxton has a 7.50 ERA in his last seven appearances.
Two bright spots have been Seth Maness, who has pitched three straight scoreless outings, and Matt Bowman, who has allowed one run in his past nine outings with a .90 ERA. Tyler Lyons hasn't pitched in 12 days, but Miguel Socolovich was called up Tuesday, which might put Lyons in some higher leverage situations.
Cardinals manager Mike Matheny is trying to keep his team's mind off the trade talk.
"You're only human when you start seeing some of the other moves teams are making," Matheny said. "I just think it's best if you can stay above that and try and figure out what you can do."
The balance of buying and selling is still delicate for St. Louis. The Cubs remain well ahead in the National League Central, but the Cardinals are still firmly in the hunt for an NL Wild Card spot.
"I think the rhetoric is picking up, for sure," Mozeliak said. "I mean, I think it's pretty clear who has players available and who doesn't."
The Cardinals utilized the 26th-man rule Wednesday for their doubleheader with the Padres, bringing up left-handed reliever Dean Kiekhefer for the second game.