Molina is scheduled to undergo surgery on Friday, while the Cardinals find themselves suddenly scouring the catching market for additional depth.
"I think every year has its hurdles, and you end up being defined on how you handle that," Mozeliak said. "This team has been together for a lot of ups and downs. They've seen players get lost for the season -- sometimes it's early, sometimes it's mid and sometimes it's late -- but they all know they have a job to do, and they'll continue to do it. Obviously, a player like Yadi who is so much a part of this club, it hurts and they all feel for him. But we have to play tonight."
Molina injured his thumb in the second inning of Wednesday's 5-2 win over the Pirates while grabbing third base as he braced himself following a feet-first slide. He remained in the game to catch the next half-inning before being replaced by Tony Cruz.
"When I felt it, right away I knew there was something wrong with it," Molina said. "That's the way I always slide. This time, my thumb got stuck in the dirt, and you saw what happened. Mentally, I'm so frustrated. You play hard, and for something to happen like that, it's bad."
Molina had his thumb immediately evaluated by team orthopedist Dr. David King, who told the Cardinals to prepare for the possibility of ligament damage. On Thursday morning, those concerns of an extended absence were confirmed with the official diagnosis.
"I almost cried," Molina said of learning the news. "For me, being out this long is frustrating. It is what it is, you have to get the rehab and get back as soon as you can."
The surgery will be followed by five weeks of healing, after which Molina can begin a rehab program. The Cardinals are hopeful that Molina will be able to return this season.
"The DL, in general, is a miserable place to be," manager Mike Matheny said. "We've got a few pitchers like that. It feels like Groundhog Day every day, and they're trying to do the work they need to do and they just feel like they're treading water. And they watch us out here fighting, and they want to jump in. This isn't going to be easy for Yadi. He's going to go crazy without question."
Cruz will become the Cardinals' primary catcher in Molina's absence, with Audry Perez ready to back him up. Perez, already on the 40-man roster, was recalled from Triple-A Memphis on Thursday. He was a September callup by the Cardinals last season and briefly appeared in two games.
Mozeliak acknowledged that he will search the market for available catchers, too, to see if an addition makes sense between now and the July 31 non-waiver Trade Deadline. With the catching market fairly thin, Mozeliak will zero in on possible veteran options, even if it is someone to serve in a backup capacity.
"I think from a standpoint of trying to replace [Molina], that's not even a logical question," Mozeliak said. "What you're doing is we need to find a stopgap. We have a lot of confidence in Cruz, that's why he is our backup. Now he's going to get an opportunity to play every day. But in the meantime, we're also going to look out and see if there is something that can help balance it out in the short term."
Molina, who has started each of the team's last 14 games, was batting .287/.341/.409 with 16 doubles, seven homers and 30 RBIs through 83 games. The six-time Gold Glove Award winner also leads the Majors with a caught-stealing percentage of 49.
The work he does behind the plate, along with his middle-of-the-order bat, has made Molina one of the most indispensable pieces on this team. He has finished in the Top 4 in MVP voting each of the last two seasons.
Molina has been on the DL just once since 2008, that coming last season, when he was slowed by a sprained right knee. Molina missed the minimum 15 games before returning.
"I've got great comfort in Tony and Perez, they know what they're doing, and I'm 100 percent confident with them," Molina said. "I know they're going to do well, and I'm going to do my best to come back as soon as possible."