The Detroit Lions were expected to be interested in Chargers offensive coordinator Ken Whisenhunt for their coaching vacancy.

Four days after the firing of Jim Schwartz, word has started to leak.

Ken Whisenhunt embraces Cardinals receiver Larry Fitzgerald in the final moments of an NFC championship game victory in the 2008 season. Whisenhunt is drawing interest from the Lions.

NFL Network is reporting the Lions have "called around" about Whisenhunt and their interest is "very strong."

Detroit can't talk with Whisenhunt until at least next week because the Chargers face Cincinnati this weekend in the wild-card round of the playoffs. But it appears the team already has initiated the vetting process.

He's a logical fit here, after quarterbacks such as a young Ben Roethlisberger, an aging Kurt Warner and a remade Philip Rivers blossomed under his tutelage. He also led the Arizona Cardinals to their first Super Bowl as head coach there.

[Related: Why Ken Whisenhunt is a fit for Lions]

Detroit already has lost its shot at a couple other logical fits, including Penn State's Bill O'Brien and former Bears coach Lovie Smith. O'Brien is headed to Houston, while Smith reportedly agreed to head to Tampa Bay.