This is Lake's first assistant coaching job at the NFL level. He played safety and cornerback for the Steelers from 1989 to 1998 and retired in 2001 after finishing his career with the Jacksonville Jaguars and Baltimore Ravens.
Lake, a four-time Pro Bowl pick, had 16 fumble recoveries and 16 interceptions as a Steeler. The 16 fumble recoveries rank fourth in franchise history.
Lake started his coaching career as an intern with the Philadelphia Eagles during training camp in 2009, then moved on to tutor defensive backs at UCLA, his alma mater, for the remainder of that season.
Lake played outside linebacker for UCLA and was a first-team all-America selection as a senior in 1988.
The Associated Press contributed to this report.