The Detroit Lions and the defending Super Bowl Champion Kansas City Chiefs kick off the 2023 NFL schedule with an interconference matchup in Kansas City on Thursday Night Football on NBC.

For the Chiefs, it's the first leg in what they hope is a repeat trip to the Super Bowl and back-to-back championships. For the Lions, it's a chance to show the hype surrounding this team the past few months is real, and they are ready to be players in the NFC playoff picture.

Here are five things to watch out for in tonight's matchup:

1. SECONDARY GAINS

Cam Sutton, C.J. Gardner-Johnson and Brian Branch all make their Lions debut tonight against reining MVP quarterback Patrick Mahomes and the league's top passing offense from last season.

Sutton, Gardner-Johnson and Branch join Kerby Joseph and Jerry Jacobs in what's looked to be a secondary that's taken a big leap forward in their ability to cover, get hands on footballs and create turnovers. Ask any player on Detroit's offense and they'll say how much more difficult it was to move the ball in the air vs. this Detroit secondary in camp than it's been in past years.

The secondary will certainly be tested in this one. In five career Week 1 openers since being named the starter in Kansas City, Mahomes has completed 121 passes on 169 attempts (71.6 percent) for 1,542 yards, 18 touchdowns, no interceptions, and a 133.9 passer rating. It's the most touchdown passes without an interception in Week 1 games in NFL history.

2. RB USAGE

It's an entirely new backfield in Detroit with David Montgomery and Jahmyr Gibbs replacing D'Andre Swift and Jamaal Williams. The Lions rushed for more than 2,000 yards and had 23 rushing touchdowns last season but think they have a chance to be even more explosive with Montgomery and Gibbs toting the rock.

Montgomery and Gibbs are expected to make a big impact in the passing game and it will be interesting to see how offensive coordinator Ben Johnson uses both backs in his scheme.

"I think they both are very versatile, so we might use Gibbs in some ways that people don't quite think we might or Montgomery the same way," Johnson said. "I'm really excited to see what they can do out on the field here this week, but we're going to use them all over the place."

3. ALL 5 UP FRONT

Montgomery and Gibbs will have the benefit of running behind arguably one of the best offensive lines in the NFL that for the first time in two seasons will have all five of their top players on the field.

Taylor Decker, Jonah Jackson, Frank Ragnow, Halapoulivaati Vaitai and Penei Sewell are expected to line up together for a regular season game for the first time, which is kind of wild to think about considering how good Detroit's offensive line has been the last two years. It should be fun to watch.

The Chiefs are likely without All-Pro defensive tackle Chris Jones. He's expected to miss tonight's game as he continues to hold out in a contract dispute. Kansas City has had a lot of turnover along their defensive front and are working in some new players tonight. The advantage on paper upfront certainly belongs to Detroit's offensive line. Can those guys make that a reality and help Detroit control the tempo offensively with their ground game and play-action pass game?

4. ARROWHEAD ENVIROMENT

GEHA Field at Arrowhead is one of the most iconic stadiums in the NFL and has a reputation as being one of the loudest. There's no doubt Chiefs fans will be riled up for a Thursday night nationally televised contest at home to kick off the season on the same night they'll raise the banner for their 2022 Super Bowl Championship.

Lions players who have never played at Arrowhead, like quarterback Jared Goff, are excited for the opportunity, but know the challenges that environment will pose.

How efficiently can the Lions' offense operate their silent counts and make sure everyone is one the same page? It's a big test for that part of the operation Week 1.

5. DEFENSIVE LINE DEPTH

This is the most talent and depth Detroit's defensive line has had in the Brad Holmes and Dan Campbell era. We've seen and heard all through training camp about the giant leap forward players like Alim McNeill and Aidan Hutchinson have made.

What impact will a healthy Charles Harris have opposite Hutchinson at the SAM linebacker spot? Can James Houston pick up right where he left off last season with eight sacks in his first seven games played? Levi Onwuzurike missed all of last season with a back injury but he's back healthy again and had a very good camp. Can he have the kind of impact the Lions hoped when they made him a second-round pick in 2021? What can we expect from Josh Paschal in Year 2?

The Chiefs are working in two new tackles in Jawaan Taylor and Donovan Smith but think this is the best offensive line they've put together in front of Mahomes. Can Detroit marry their rush and cover and make things difficult for Mahomes? It just might be the key to victory for Detroit.