Fickell had been previously mentioned as a candidate at Cincinnati, but on Wednesday, a source said Bearcats athletic director Mike Bohn was in Columbus, Ohio, meeting with Fickell.
The 43-year-old Fickell went 6-7 in 2011 as the Buckeyes interim coach following the firing of Jim Tressel. He was retained by Urban Meyer when Meyer took over in 2012.
Fickell is a former Ohio State defensive lineman who has been on the staff since 2002. He played defensive line for the Buckeyes from 1993-96.
Fickell is listed as assistant coach/defensive coordinator, linebackers on the Ohio State coaching staff directory. Greg Schiano is listed as associate head coach/defensive coordinator.
Schiano's name has been attached to several openings including the just-filled Oregon job. A source close to the process told CBS Sports on Wednesday that Schiano wasn't likely to be the choice at South Florida. Schiano had previously coached the NFL's Tampa Bay Buccaneers.
Petrino is the younger brother of Louisville coach Bobby Petrino. Ironically, contact was made between Bobby and Western Kentucky four years ago to the day on Wednesday.
Paul Petrino is 14-33 in three seasons at Idaho. The Vandals just completed their best season in 19 years, finishing 8-4 in 2016. Paul's interest in the Hilltoppers is obvious considering his brother's ties to the program.
247Sports was first to report the link between Paul Petrino and Western Kentucky.
While Lane Kiffin remains a candidate at South Florida, he may not have an endorsement from a member of the current staff.
David Reaves is the Bulls' associate head coach/tight ends coach. Reaves is also Kiffin's soon-to-be-former brother-in-law. Kiffin's wife, Layla, filed for divorce in March citing "irreconcilable differences."
One source close to the South Florida search told CBS Sports "that well has been poisoned" in regards to Kiffin's candidacy at South Florida.
Current USF athletic director Mark Harlan worked at UCLA as a senior associate athletic director from 2010-14. Kiffin was head coach at rival USC from 2010 to five games into the 2013 season, giving Harlan a first-hand look at Kiffin's coaching.