"I train to play 174 games because that's what it takes to be a Champion, [sic] I'm not tired and the day I feel tired I'll express it myself. #misinforming"
Hours later, Molina spoke to the media at length about his frustration and why he chose to make it public via social media.
"I had to defend myself," Molina explained. "When you see a manager quote you that way, that you look tired in the middle of the game running the bases, then people are going to think that you are when you're not. … That's not true. I'm ready to go. I'm not tired."
And, in fact, Matheny agreed.
Matheny never used the word "tired" to describe Molina in his pregame comments on Thursday, though he did make an unusual midsentence pivot after being asked why he chose to sit the veteran catcher. After noting that Carson Kelly's familiarity with spot starter Luke Weaver factored into the decision, Matheny added:
"Also, Yadi has caught a lot. Yesterday, just kind of watching him around the bases, too, you could tell that he … he's doing great. He's swinging the bat well. He's playing well defensively."
The report in the St. Louis Post-Dispatch did not include the second part of that thought, and Matheny clarified Friday that he wasn't implying fatigue in the statement.
"Tired was never a part of it. Fear of injury was," Matheny said. "I said I saw him go into third base [on Friday], and if you guys were watching, you saw exactly what I saw, a guy that was limping going into third. I actually called time and I said, 'Is he OK?' I was worried about whether it was an ankle [injury], whether it was a knee. And I said to myself at that particular time, 'He's playing really well. I'm going to give him a day. With Weaver and Carson working together, that makes a lot of sense. Let's get him a day.' At that point, my mind was made up."
As of Friday afternoon, Molina and Matheny had yet to discuss the issue. Molina said he had "no regrets" about the decision to air his grievances the way he did, but also noted that he has "always respected Mike."
The two have had a unique relationship that dates back to Molina's days as a minor league catcher in the organization. Molina was called up to replace an injured Matheny in 2004 and took over as the Cardinals' starting catcher a year later. Matheny left as a free agent.
Since returning as manager in 2012, Matheny has repeatedly deflected criticism about not resting the veteran catcher more often. Matheny, who once told Brewers manager Phil Garner that his goal was to start 162 games in a season, understands and appreciates the desire Molina has to be in the lineup every day.
"I think that's a great way to prepare," Matheny said. "That's a great way to think about it -- no matter what, I'm going to be in there."
Indeed, Molina has shown a special ability to withstand the attrition of his position. The eight-time Gold Glove Award winner made a Major League-high 142 starts behind the plate last season and, at age 35, he leads all catchers in starts (85) and innings caught (738) in 2017.
What makes the situation a bit more complex now, however, is the arrival of Carson Kelly. Called up last week, Kelly, the top catching prospect in baseball, now stands to serve as Molina's backup for the coming years. Because Molina is signed through 2020, there's some natural curiosity about how playing time will be split between the two as Molina continues to age.
Matheny attempted to head off some of that potential tension by pulling Molina aside on the team's flight to Chicago last week to inform him of Kelly's arrival.
Molina stressed that his Instagram comments were not meant to be an affront toward Kelly.
"Let me clear up something: I've got no problem with Carson here," Molina said. "I'm going to help him out the way I can, the best way I can. He's a great kid, a great catcher, great talent."
Nevertheless, the Cardinals understand that Molina's social-media message casts an impression of clubhouse dissension. Speculation of discord was further fueled by the fact that multiple teammates "liked" the Instagram post.
Matheny, who acknowledged that he felt tension brewing in the clubhouse before this, hopes that any further issues can be resolved so as not to distract from the team's attempt to make a climb in the National League Central.
"This is one of those situations where, 'OK, we've got this. What do we do with it?'" Matheny said. "And the answer is, we go play baseball. This is one of those things we compartmentalize [and] we talk through. This is going to be something I believe -- and you've heard me talk about the toughness of our club -- it's just another opportunity for us to move forward."