ALLEN PARK, Mich. -- Detroit Lions general manager Bob Quinn decided to make a change Monday, firing head coach Jim Caldwell after four seasons. And for the first time in his tenure, Quinn will need to pick who will run his football team.

Quinn has some obvious ties with the New England Patriots as well as connections with other potential coaches across the league. With that in mind, here are some potential candidates to watch out for as the Lions' search begins.

The Patriots ties

Josh McDaniels, offensive coordinator, New England: The 41-year-old might be one of the favorites. Quinn has familiarity with him from McDaniels’ two stints with the Patriots. McDaniels and Quinn started in New England within a year of each other. McDaniels has prior head-coaching experience, posting an 11-17 record in two seasons with the Denver Broncos. Like his mentor, Bill Belichick, if McDaniels has learned from his first head-coaching stint, he could have massive success in his second. He has an innovative offensive scheme that could fit well with Detroit’s current personnel.

Matt Patricia, defensive coordinator, New England: The 43-year-old, who might have been a nuclear engineer had he not gone into coaching, doesn’t have head-coaching experience, but he has created innovative defenses and has been able to get the most out of his players. He had the No. 1 scoring defense in 2016 and his defenses have consistently been in the top 10 in fewest points allowed. Detroit is a place where he could fit well, too, because his blue-collar style might endear him to the city. ESPN Insider Adam Schefter has reported the Lions have requested to interview Patricia.

Mike Vrabel, defensive coordinator, Houston: Quinn knows the 42-year-old from Vrabel's time as a linebacker in New England. He has only one year of experience as an NFL coordinator but is considered one of the brighter young coaches in the game. Plus, his experience comes with the front seven, which might be the most glaring need on Detroit’s roster. Pair him with a strong offensive coordinator and it could be a good match.

The assistants:

Kris Richard, defensive coordinator, Seattle Seahawks: The 38-year-old has been Seattle’s defensive coordinator the past three seasons, producing a top-10 unit in 2015 and 2016. He also served as secondary coach before that, helping to develop the Legion of Boom, and as a defensive coordinator has been particularly good against the run.

Frank Reich, offensive coordinator, Philadelphia Eagles: The 56-year-old has done a great job with the Eagles' offense and there could be some familiarity in the transition for quarterback Matthew Stafford because Reich worked with Caldwell in Indianapolis from 2008 to 2011, including two seasons as quarterbacks coach. He also understands the Lions, as he spent the final two years of his playing career as a backup in Detroit.

John DeFilippo, quarterbacks coach, Philadelphia Eagles: The 39-year-old has done a fantastic job with Carson Wentz and has been coaching since 2000. He’s been with six NFL teams already -- not including internships while he was a quarterback at James Madison. He would be a little bit unconventional, but he has potential to be a good head coach who understands delegation. He grew up around it, too, as his dad is former Villanova and Boston College athletic director Gene DeFilippo.

Steve Wilks, defensive coordinator, Carolina Panthers: The 48-year-old is the assistant head coach in Carolina and was promoted to defensive coordinator after Sean McDermott became Buffalo's head coach last year. He's primarily been a secondary coach his whole career and has experience with three NFL teams -- Carolina, San Diego and Chicago. Schefter has reported the Lions have requested to interview Wilks. He's going to be a popular candidate.

The long shots:

Jon Gruden, ESPN analyst: He’s always going to be on these lists. But the Lions might offer him enough in terms of personnel to consider jumping back into coaching. The Lions have a top-level quarterback, a good group of pass-catchers and a strong secondary. Gruden is 95-81 overall as a head coach, with four seasons of 10 wins or more and only three sub-.500 campaigns in 11 years. Again, it’s worth a call if Quinn thinks he can work with him.

Jim Harbaugh, head coach, Michigan: Very, very long odds here, but if for some reason he has the NFL itch now, he wouldn’t have to move his family, and that could be attractive. But there’s no reason to think this will happen.

David Shaw, head coach, Stanford: He’s pushed away a lot of other NFL inquiries, but there is some connection to the Detroit area. He played high school football in Rochester Hills, Michigan, and his father was an assistant coach for the Lions. He has a 73-20 record as Stanford’s head coach.

The non-starters:

Jim Schwartz, defensive coordinator, Philadelphia Eagles: It’s actually a shame, because Schwartz could fit well in Detroit if he learned from his prior coaching experience. However, considering the way his tenure ended, with him cursing at fans after a collapse in 2013, it would be tough to see the Lions even considering him this time.

Teryl Austin, defensive coordinator, Detroit Lions: I’ve long been impressed by Austin and believe he has everything you could want in a head coach, from demeanor to X’s-and-O’s knowledge to savvy with the media. If given the chance, he has potential to be a great head coach. But Detroit, where his boss was just fired, would be a tough sell. ESPN Insider Josina Anderson is reporting Austin will interview with the Lions on Tuesday.

Another name to watch: Harold Goodwin, offensive coordinator, Arizona. Goodwin has been Arizona’s offensive coordinator since 2013 and has familiarity with the state of Michigan. He played offensive line for the Wolverines and spent time as a graduate assistant at Michigan before becoming an offensive line coach at Eastern Michigan from 1998 to '99 and Central Michigan from 2000 '03 before heading to the NFL, where he coached with Chicago, Pittsburgh, Indianapolis and Arizona.