The 40-year-old Molina owns the Vaqueros de Bayamón, who play in the Baloncesto Superior National league. Bayamón beat San Germán 75-61 on Saturday to clinch its 16th BSN title.
Molina was placed on the restricted list Saturday and missed the final two games of St. Louis' weekend sweep in Arizona. The veteran catcher was in the starting lineup for the opener of a five-game series at the Chicago Cubs.
"That's a business trip," Molina said. "I had to be there for the team and for the city. ... It was a great experience."
Asked how he weighed his duties with the NL Central-leading Cardinals versus his ownership of Bayamón, Molina said he had to go on the trip.
"The people need it in Puerto Rico. Obviously, to be around there with the people, with the team, it's good for the people down there," the 10-time All-Star said. "So I did what I had to."
To make room for Molina on the roster, fellow catcher Iván Herrera was optioned to Triple-A Memphis and placed on the Cardinals' taxi squad.
The team also announced that reliever Ryan Helsley had been removed from the paternity list and placed on the restricted list.
Molina had three hits in the Cardinals' 5-1 victory over the Diamondbacks on Friday night. Heading into the series at Wrigley Field, he was batting .222 with two homers and 12 RBIs in 52 games in what likely will be his final big league season. In Monday's 1-0 victory over the Cubs, Molina went 0 for 3.
St. Louis manager Oliver Marmol said Molina brought up the trip during the last series of the team's previous homestand.
"It went well," Marmol said of his talks with Molina. "He's a grown man. We had the conversation and we left the room on the same page as far as him going back and being in the lineup today."
Molina has spent his entire career in St. Louis, breaking into the majors in 2004 and winning two World Series titles with the Cardinals. He said he appreciated the team's understanding when it came to the Puerto Rico trip.
"It was tough," he said. "Obviously you want to be here with the team and do your job. But obviously, my business side, you got to be there with the team and you got to be there for the people over there, too. So I mean I'm glad it was only two days."
The Associated Press contributed to this story.