Cardinals catcher Yadier Molina is expected to be out for one month after being hit in the groin by a foul tip during Saturday's win over the Cubs. (0:20)

ST. LOUIS -- Mike Matheny knows all too well the usual aches and pains associated with catching in the major leagues.

That experience told the St. Louis Cardinals manager that the pain Yadier Molina was in after he was hit in the groin by a foul tip on Saturday was not normal.

Matheny's intuition proved correct later that night, when Molina underwent surgery for what the team called a "pelvic injury with traumatic hematoma." The eight-time All-Star was placed on the 10-day disabled list on Sunday, and he's expected to miss at least four weeks with the injury.

"It's like nothing you've ever felt," said Matheny, who was a catcher during his 13-year playing career. "You're always just hoping it's one of those that just takes a couple of minutes, then it's manageable. But you could see that was a different level."

Molina left Saturday's game against the Chicago Cubs after being hit when Kris Bryant tipped a 102 mph pitch from reliever Jordan Hicks. Molina immediately fell to the ground and was replaced by Francisco Pena, who was also in the starting lineup for the Cardinals a day later against the Cubs.

Bengie Molina, also a former catcher in the majors and Yadier's older brother, said the surgery lasted 45 minutes. He said doctors were able to save both of Molina's testicles.

The elder Molina visited his brother after he was released from the hospital Sunday morning and was encouraged by how he looked.

"I was expecting him to come in a wheelchair or [need] a little help," Bengie Molina said. "So I went over to the door, and when I saw him, he was walking."

The 35-year-old Yadier Molina is hitting .272 with six home runs and 17 RBIs this season. He was replaced on the active roster by catcher Carson Kelly, who was called up from Triple-A Memphis on Sunday.

St. Louis President John Mozeliak said Molina was told by doctors to rest for the next week before slowing starting to work his way back into shape.

"Really, it's just going to be just take each day as it comes," Mozeliak said. "But hopefully, it's not too long."

Both Mozeliak and Matheny joked about Molina's competitiveness and what a difficult time doctors are likely to have keeping the eight-time Gold Glove winner from doing too much too soon during his recovery.

"He always feels bad that he's not able to be here," Matheny said. "That's just how he's wired."