Who's Next HC for Panthers?

It wasn't long after Carolina fired Ron Rivera after nine seasons that speculation began to swirl on Tuesday as to who will be take his place. 

But narrowing down a surefire replacement isn't easy. 

There's still so much to learn about second-year coach David Tepper. Other than winning, what kind of football does he envision the team for which he paid a record $2.275 billion playing? And who will be lining up for the Panthers could determine much of that, considering the future of franchise quarterback Cam Newton is something that won't be decided until the offseason (and much of that depends on his health).

“There are so many different direction they can go in," said Frank Garcia, a former offensive lineman who played for Carolina from 1995-2000. "David Tepper obviously will exhaust all his resources to find the right fit, to match what he wants for the direction of the team. 

“But the Panthers have never had an offensive-mind head coach. It will be interesting to see if Tepper flips the script and go in that that direction. But ultimately he’s going to find a guy who fits his beliefs and standards.”

A retread or a first-timer? A coach who likes to pile up points or a gritty defensive-minded coach? Again, it's all up for debate and speculation at the moment. And just about anyone who's twirled a whistle is a candidate right now.

Here are four names to remember:

Greg Roman

• Greg Roman, 47 -- Currently the offensive coordinator in Baltimore, Roman has more than 20 years of NFL experience. He was the OC under Jim Harbaugh for four seasons in San Francisco, including the 49ers' run to Super Bowl XLVII. What he's doing in Baltimore with quarterback Lamar Jackson is both innovative and exciting -- something Carolina fans have craved.

• Josh McDaniels, 43 -- He's a retread, but don't discount him. The offensive coordinator and quarterbacks coach in New England, McDaniels has head coaching experience, going 11-17 during a two-year stint in Denver. His time there was tarnished further by an incident in which Denver's director of video operations recorded a 49ers practice. Still, McDaniels has been credited with innovative offensive schemes and has been a part of six Super Bowl victories thanks to two long terms with the Patriots (2001-2008, 2012-present). Those rings can go a long way toward polishing his candidacy.

Matt Rhule

• Matt Rhule, 44 -- Rhule has not only returned Baylor football to relevancy after the scandals that happened under former coach Art Briles, he has the Bears playing for the Big 12 Championship as well as a short at the College Football Playoffs. Rhule knows both sides of the football, is a player's coach and, being only 44, could invigorate younger generations of fans.

Dan Mullen

• Dan Mullen, 47 -- Wrapping up his second season as Florida's head coach, Mullen has no NFL experience and has never seriously been linked to an NFL opening. Yet, his name has popped up in a few circles and his profile does fit the league's current direction of younger, offensive-minded coaches who lean toward innovation. Mullen definitely fits description during his time as head coach at Mississippi State and as offensive coordinator for the Gators during their national title-winning seasons of 2006 and 2008. Some of the players he's mentored have enjoyed NFL success, including Dak Prescott and Alex Smith (when Mullen was quarterbacks coach at Utah). Tim Tebow didn't have much success at the next level, but he won a Heisman Trophy under Mullen's tutelage, indicating the coach can leverage his personnel.