Maher watched batting practice before Sunday's game against the Cardinals from behind the batting cage donning a black Mets cap.
"When I was 6 years old, that's when I started being a Mets fan because that's when they came into existence," Maher said in a video message released by the club. "I really never wavered in my love for this team. We were thrilled in '69, we were thrilled in '86, and I think we're going to be thrilled again very soon."
It was unclear when Maher finalized his purchase of a share of the team, but the club sold 12 minority ownership stakes -- valued at $20 million each -- in March. That allowed the team to repay a $25 million loan to Major League Baseball and a $40 million loan to Bank of America. The only shares that were public at the time were purchased by the team's parent company, Sterling Equities, and SNY, a partially team-owned cable network.
"What can I say?" Maher said in the video message. "'You gotta believe,' and I do."
Steven Miller is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.