Chicago.Cubs.MLB.com

By Carrie Muskat / MLB.com

The Cubs retired Ron Santo's No. 10 on Sept. 28, 2003. (Brian Kersey/AP)

The lucky fans who delayed their exit from the weekend Cubs Convention on Sunday watched a sneak preview of "This Old Cub," a 90-minute documentary about Ron Santo, the team's former third baseman and current WGN Radio broadcaster. And the crowd gave the film a rousing standing ovation at the end.

"I was blown away by that," said Ron's son, Jeff Santo, who produced, directed and filmed parts of the movie. "It's emotional. To see them give a standing ovation at the end, I was just blown away."

The documentary, which will be released in Chicago and Arizona theaters in March by Emerging Pictures, is an emotional ride. It details Santo's life and how he has dealt with his health issues, primarily the loss of both legs because of complications from diabetes.

Santo's hospital time and rehab from the second amputation is interspersed with clips from his days with the Cubs, for whom he played from 1960-73. Joe Mantegna narrated the film, and there are interviews with players, actors and broadcasters, many touting Santo's abilities, how influential he was to them, and how he deserves to be in the Hall of Fame.

But Santo didn't make it to Cooperstown in February 2003 when the Veterans Committee voted, and the build-up and subsequent disappointment is featured.

Sunday's audience sat in stunned silence during the revealing scenes showing Santo putting on his two prosthesis or giving himself an insulin shot. He chides family members at one point for helping him too much, saying he has to learn to do it himself.

The crowd laughed heartily at replays of Santo's exchanges with WGN Radio announcer Pat Hughes, including clips about singeing his toupee in a press box and dealing with a man whose girlfriend was a New York Mets fan.

Santo's advice? "Get rid of her," he said.

"We thought we'd get laughs there," Jeff Santo said of the movie.

There are famous -- and infamous -- Santo moments. He talks about clicking his heels in 1969; how he dealt with a diabetes episode during a game; and, of course, his "Oh, no" call in 1998, when Cubs outfielder Brant Brown dropped a fly ball in Milwaukee.

There were more than a few tears by movie viewers watching Santo riding his motorized scooter and heading off down the street with 4-year-old grandson Sam on his own scooter after Santo returned home from his second amputation.

Viewers could feel Santo's bitterness toward the Mets in 1969.

"When we were watching it together [for the first time] and we came to the '69 part, he said, 'I can't believe we didn't win it,'" Jeff Santo said.

There also are some bad sportcoats and hairstyles featured from the 1969 team -- many of which the players probably didn't want captured on film. And there are clips from Santo's playing days that reinforce the terrific third baseman he was.

Santo, who turns 64 in February, was not at Sunday's sneak preview. He did attend the Cubs Convention and threw out the first pitch Friday in his first public appearance since undergoing surgery this offseason to remove tumors from his bladder. He recently signed a three-year contract with WGN Radio and promises to be ready for Spring Training.

"It's difficult for him to watch," Jeff said. "It's 91 minutes of him."

The elder Santo said he would not let anyone else do such a movie except for his son. At one point in Santo's rehab at home, he falls and knocks over Jeff's camera, resulting in a tumbling sequence. Once Jeff gets his father back on his feet, Ron quips, "Did you get that on camera?"

The Cubs made Santo the lowest offer of all the Major League teams interested in him, yet he still signed, saying there was something about Chicago and Wrigley Field that he liked. His relationship with the team, the city and the fans is an intense love affair that has not waned over the years. The film includes the ceremony last Sept. 28, when Santo's No. 10 was retired at Wrigley Field.

All Santo fans will adore the emotional film.

"He's the strongest man I've ever met in my life," Cubs marketing director John McDonough said in introducing the movie Sunday.

The documentary definitely supports that.

"I'm really proud of it," Jeff Santo said.

Carrie Muskat is a reporter for MLB.com. This story was not subject to approval by Major League Baseball or its clubs.