Lynn's command was not at its best, evidenced by three straight walks issued in the fourth to load the bases. But that was not Matheny's biggest concern.
What the Cardinals' manager did feel needed to be addressed with Lynn was how he handled adversity, and how Lynn may have let his emotions get the best of him on the mound.
"It's not the kind of game he wants," Matheny said on Sunday. "I think the bigger message really was that's not how he needs to respond when games start to go in that direction. It's just a part of the maturing process."
Lynn was noticeably both pumped up and frustrated at different points throughout the game. He clapped his hands together and threw his arms up after striking out Erik Bedard to escape that jam in the fourth inning. But Lynn also appeared "defeated," as Matheny put it, when his command waned.
"We can't help but see it," Matheny said. "The thing is, that leads to how the umpire views the strike zone and views you and your team. That's how the opposition sees you, a chink in the armor. No good comes from that. It's the consistency that's needed on the mound all the time. His stuff's too good."
Matheny hopes the conversations he, the coaching staff and Lynn's teammates have with the 25-year-old right-hander can help him harness his emotions.
After winning 10 of his first 13 starts this season, Lynn has gone 2-1 with a 4.58 ERA since the All-Star break.
"When you win your first however many games, everything's going great. But you really find out, and the league finds out, a lot about when you don't have your best stuff," Matheny said. "How are you going to compete? And competing really comes down to how you handle that adversity, whether it's a tight zone, whether it's plays not happening behind you.
"He needs to pay close attention because there's little things he's missing in his game. Once he puts it all together, to me I see a really good, long career. But, to me, there's still some things I see that need to be fixed."