In January 2018, Molina expressed his plan to retire following the 2020 season when his contract would expire. As batterymates, Wainwright and Molina had accumulated more starts together than any other in franchise history. He passed Bench for two milestones early in the season: for 13th place in major league history in innings caught with on April 14 while playing the Cincinnati Reds, and 16th in games caught versus with 1,743 on May 2 versus the Chicago White Sox. Molina doubled versus Cincinnati on April 22 to give him 338 for his career and tie Ozzie Smith for tenth place in Cardinals' history. On May 5, Molina exited the game after a foul tip struck him in the groin. The next day, on May 6, Molina underwent emergency surgery for a pelvic injury with traumatic hematoma.