Wilken, who is in his seventh season with the Cubs, has more than 30 years of baseball experience.
Wilken still will scout players for the annual First-Year Player Draft, but now also will scout players at the Major League, professional and international levels. He also will help evaluate players throughout the Cubs' system.
"We're pretty excited about the opportunity to do this," vice president of scouting and player development Jason McLeod said Saturday. "It allows us to utilize [Wilken's] strengths and even reach more areas of the organization. I know he's really excited about it, and it makes him feel -- not re-engerized like he needed it -- but he's been in amateur scouting for so long and done such a great job there, I know he felt like he was ready to contribute in other departments in the organization."
Wilken was named the 2006 East Coast Scout of the Year by the Scout of the Year Foundation after his first year with the Cubs. He has drafted and signed current Cubs second baseman Darwin Barney, left-hander James Russell, right-hander Jeff Samardzija, center fielder Brett Jackson and third baseman Josh Vitters. His four first-round selections -- Tyler Colvin (2006), Vitters (2007), Andrew Cashner (2008) and Jackson (2009) -- all reached the Majors with the Cubs.
Wilken previously worked for Tampa Bay and Toronto in a variety of capacities. While with the Blue Jays, he helped sign and develop right-handers Chris Carpenter and Roy Halladay, as well as outfielder Vernon Wells and infielder Michael Young.
Madison comes to the Cubs after spending the past three years as director of amateur scouting for the Padres. He began his career as an associate area scout for San Diego in 2002 and also has worked in the Pirates (2002-05) and Cardinals (2008-09) organizations. He was with the Padres between his stints in Pittsburgh and St. Louis.
"Jaron understands our systems and the processes that we want to put in place, and is a talented evaluator himself, and a great manager of scouts, very organized and detailed," said McLeod, who worked with Madison in San Diego. "For us, it's a win-win to be able to do this."
Madison, 36, is a 1998 graduate of Long Beach State, where he also coached from 2001-02. He also received his Masters in sports management from the University of San Francisco in 2002.
"Obviously there was familiarity with [general manager Jed Hoyer] and I, and he's never worked with [president of baseball operations Theo Epstein], so I know that was something that was attractive to him, as well as this franchise and what we're trying to do," McLeod said. "I think, ultimately, the relationships and this particular franchise is what swayed him to want come work over here."