Lacewell was later the longtime director of scouting for the Dallas Cowboys of the National Football League (NFL).
Lacewell became assistant head coach under Barry Switzer in 1973, and the teams won six Big Eight titles and two national championships in the ensuing years.
He also led the program to four consecutive appearances in the NCAA Division I-AA playoffs, with the 1986 team making it all the way to the championship game before losing to Georgia Southern.
After head coach Jimmy Johnson left the franchise on March 28, 1994, the subsequent drafts made by the Cowboys came under heavy scrutiny in the media and with the fans, as they were never able to replenish the talent base and holdovers of the Super Bowl teams of the early 1990s.
In January 2005, two seasons after the arrival of head coach Bill Parcells, he retired and moved into a talent consultant role, while being replaced by Jeff Ireland, who was promoted to Vice President of Pro and College Scouting.