Only one team — the Rams — has interviewed former NFL coach Jim Fassel, who has expressed interest in the Raiders’ head-coaching vacancy.

One of the offseason’s confounding issues is why coaches like Brian Billick and Jim Fassel can’t land head-coaching jobs — and why they’re even struggling to get interviews.

Billick’s work and accomplishments are well-documented. In his 18 NFL years, his teams went to the playoffs 13 times. He won a Super Bowl with Baltimore. Just as impressive, five of Billick’s assistants in Baltimore went on to become head coaches in one of the least talked about but most impressive head-coaching trees.

After finishing as a runner-up for the Redskins’ head-coaching job last offseason, Jim Fassel is in the running for the Rams’ vacancy this offseason.

Jim Fassel watched from the roof of Giants Stadium in East Rutherford, New Jersey as the Twin Towers in lower Manhattan collapsed in the Sept. 11 terrorist attacks. Fassel, who was head coach of the Giants in 2001, and the team visited the site a week later to support the first responders.

When hot head coaching candidates are debated, Giants defensive coordinator Steve Spagnuolo usually is mentioned, rightfully, near or at the top of the list.

But New York’s other coordinator, offensive Kevin Gilbride, also has coached his way into the conversation.