Dauer, first-year manager of the Missions, set a pair of American League single-season fielding records for second basemen during his 10-year playing career with the Orioles, including 425 consecutive errorless chances during the 1978 season.
Spangenberg, 22, was more or less a sponge after landing in San Antonio, where he helped the Missions to the Texas League title. If Dauer talked defense, Spangenberg listened intently.
"I love playing for Richie," Spangenberg said recently, following a game in the Arizona Fall League for the Peoria Javelinas.
"He has such a wealth of knowledge so you try to listen to everything he says. He can give you all those little pointers here and there that end up making a world of difference."
This was especially important for Spangenberg, who played mostly third base and shortstop leading up to the 2011 First-Year Player Draft, though the Padres always envisioned him as a second baseman.
Randy Smith, the Padres' vice president of player development and international scouting, saw some big differences in Spangenberg's defense after the promotion to San Antonio, especially when it came to his positioning, something Dauer worked closely with Spangenberg on.
"I thought he really improved when he made the jump to Double-A," Smith said. "And working with Rich Dauer, his defense really improved. I think he's healthy and is getting more comfortable as a second baseman. You have to remember, that was a position change for him."
Spangenberg, ranked as the Padres' No. 14 prospect by MLB.com, made just four errors in the 76 games after the promotion for the Missions, who defeated Arkansas for the Texas League crown.
Spangenberg is currently in Arizona for the second time in as many years, playing for Peoria and working on, you guessed it, his defense and offense. He was hitting .305 with two home runs and seven RBIs in 17 games.
It was in Arizona last fall when he hit .345 in eight games, the start, he said, of finding his swing and a consistent approach that he carried into the regular season in 2013.
"I got my confidence back here in the Fall League the year before, starting seeing pitches again, taking a better approach and have a more consistent swing," Spangenberg said. "I think when I have all that ... that's things are going good."
Spangenberg has produced a .291/.357/.392 line with 88 steals in his first 300 Minor League games and 1,328 plate appearances. Five hundred and 72 of those plate appearances came this past season, which, he said, was much needed after a concussion caused him to miss six weeks in 2012.
Spangenberg was struck in the back of his head with a ball while playing catch with a teammate. He had what he called a splitting headache at first, one that wouldn't go away. He never thought he would miss so much playing time, but the concussion symptoms were slow to go away.
"I tried to come back too soon and ended up with a headache that was even worse. That wasn't the best experience," said Spangenberg, who hit .271 in 98 games with Lake Elsinore in 2012. "I've never been hurt like that in my life. I had to sit and wait until all my symptoms went away.
"That was the most frustrating thing about it. You can't do anything about it."
A left-handed hitter, Spangenberg showed more extra-base hit potential in 2013 than he showed in his first two seasons with 38, including 23 doubles. His 150 combined hits and 36 steals were also bests in his young career.
"He's a good athlete," Smith said. "I think he's taking that athleticism and becoming a good baseball player."