Green lasted only three seasons while Graves was eventually let go a year ago.
Caldwell, the Lions’ 26th coach, will be officially introduced during a 4 p.m. news conference on Wednesday at the Lions’ headquarters in Allen Park, Mich.
He will be only as good as the staff he hires.
Here are some of the rumored candidates who are possibilities for those jobs:
— Teryl Austin, who worked with Caldwell in Baltimore, for defensive coordinator. Austin is the Ravens’ secondary coach and a former Michigan assistant (1999-2002) under Lloyd Carr. Austin has been on staffs that made three Super Bowl appearances - with Seattle (2005), Arizona (2008) and Baltimore (2012). His only experience as a coordinator was at the University of Florida in 2010.
— Bill Lazor, quarterbacks coach with the Philadelphia Eagles, for offensive coordinator. Lazor was previously a coordinator in college at Virginia and Buffalo. He’s a former all-Ivy League quarterback at Cornell.
— Clyde Christensen, currently the Indianapolis Colts’ quarterbacks coach, for offensive coordinator. Christensen, a former quarterback at North Carolina (1977-78), was the Colts’ offensive coordinator under Caldwell in 2010-11.
— Andy Moeller, another Ravens’ assistant, for offensive line coach. Moeller has been with Baltimore the last five years. He is the son of former Michigan coach Gary Moeller, was a linebacker for the Wolverines from 1983-86 and an assistant coach from 2000-07.
— Wilbert Montgomery, a former NFL player, for running backs coach. Montgomery spent nine years in the league, the first eight with Philadelphia and the last one in Detroit. He rushed for 1,512 yards in 1979. His coaching resume includes two years as a Lions’ assistant in 2006-07.
— Ron Prince, currently Rutgers’ offensive coordinator, in some type of position with the offense. Prince was the head coach at Kansas State from 2006-08 and spent two years on Caldwell’s staff in Indianapolis as an assistant offensive line coach.
— Former Ohio State coach Jim Tressel for a possible coach or consultant role. Tressel won a national championship during his 11 years with the Buckeyes before being forced out in the wake of the Tattoo scandal. He was a consultant with the Colts during Caldwell’s final year there in 2011. Tressel has since been working at the University of Akron as the Vice President for Student Success.