Riggins feels he suddenly understands how little things like a bloop hit or a swinging bunt could disrupt Zambrano's concentration.
"That's his key," Riggins said. "He doesn't believe that a guy should get that type of bloop hit off of him.
"When the player reaches first base, it's still bothering him, and that affects his approach to the next hitter."
Riggins presented an example of how Zambrano recently short-circuited during a start in Los Angeles.
"He was rolling along and we were scoring some runs," Riggins said. "Then he lost some concentration. It was just a couple of little hits that did it. Then he lost his location a little bit as well.
"After the inning, [Geovany Soto] and I talked to him, and he got back into his game. That's something that he's worked on and he's better at now. He's not letting all those little things get him out of the ballgame."
Zambrano goes into Monday night's game in Cincinnati with a 10-game road winning streak, dating back to Aug. 14, 2010. Zambrano and Steve Trachsel share the Cubs' longest road winning streaks since Guy Bush won 13 straight in 1919.
In order to extend that streak, Riggins wants starters like Zambrano to concentrate more on location than velocity.
"These guys have tough jobs," Riggins said. "They have to stay focused for 110 pitches out there. It takes a special guy to do that. That's why commanding all of your pitches, rather than just worrying about your velocity, is a key for a guy like Zambrano."
Zambrano is 16-10 lifetime vs. Cincinnati with a 3.06 ERA.