The preparations for Sunday’s AFC South battle are now behind the Jacksonville Jaguars and Indianapolis Colts and all that is left to do is take the field and see who the better team is. With it being a divisional game in which both teams feel is a must-win, the battle is going to come down to a few key matchups. Here are five matchups that we’ll be watching as both teams duke it out at Lucas Oil Stadium Sunday:

LB Myles Jack vs. RB Marlon Mack

Marlon Mack will enter Sunday’s game as one of the Colts’ top weapons, while the Jags’ defense will enter it ranked 22nd against the run. They’ve had several blunders against the run as fans witnessed against the Carolina Panthers and Houston Texans (Week 9). In both of those games, they allowed over 200 rushing yards, which can’t happen against Marlon Mack, who is the league’s ninth leading rusher with 753 yards.

With the Colts ruling two of their speedster receivers out in T.Y. Hilton and Paris Campbell, they might elect to run the ball more than they ever have this year. It will then fall on Myles Jack as the defense’s enforcer at linebacker to make sure Mack doesn’t get out of hand. The Jags’ defense will need to be fundamentally sound, too, by not allowing a lot of broken tackles which Mack is good at taking advantage of.

DL Calais Campbell vs. OG Quenton Nelson

As we witnessed last year, there are going to be times where the Colts’ best offensive lineman, Quenton Nelson, lines up against the Jags’ best defensive lineman in Calais Campbell. The veteran had some success against Nelson last season, who was then a rookie, but he’s a significantly better player this year, upping his Pro Football Focus grade from a 74.3 in 2018 to an 89.4 this season.

As previously stated, the Colts could look to run the ball and Nelson is a big part of what makes them successful there, so it will be imperative for Campbell to keep him from reaching the second level. Campbell and company also need to win against Nelson during passing downs as Jacoby Brissett has shown the tendency to hold on to the ball too long in the past.

CB Tre Herndon vs. WR Zach Pascal

The Colts may be without Hilton and Campbell Sunday but that doesn’t necessarily mean they don’t have threats through the air. In fact, Zach Pascal statistically has 13 less receiving yards than Hilton, who leads the team in receiving with 360 yards. He also has on less touchdown than Hilton, who has five. That said, with a 75.0 PFF grade to his name, he’ll be the Colts’ best receiver on the outside Sunday.

Like most opponents have, the Colts will likely target Tre Herndon early and often and will likely target him when he and Pascal are lined up against each other. It’s on Herndon on whether or not he’ll be up for the task as he’s had some highs and lows since the Jags traded Jalen Ramsey.

RB Leonard Fournette vs. LB Darius Leonard

We’ll call this one the Battle of the Leonards.

As we’ve said multiple times, fans should expect a physical one in between the tackles. With Leonard Fournette only receiving 11 carries Week 9 against the Houston Texans, coordinator John DeFilippo should be looking to get him more involved Sunday because he’s the engine for the Jags’ offense.

Meanwhile, Darius Leonard is viewed in the same light for the Colts’ defense. He’s been a tackling machine, accumulating 10 or more tackles in four of the games he’s played in. Simply put, that points to him being very active if Fournette receives more than 20 carries as he should.

WR D.J. Chark Jr. vs. CB Kenny Moore II 

This matchup is simply a battle between the Jags’ best receiver and the Colts’ best corner who will see a lot of each other Sunday. Chark has emerged as the Jags’ best receiver this year and is one of the league’s most improved players with just under 700 yards to his name for six touchdowns. With Nick Foles returning to the lineup, the two could be looking to link up deep as they did for the Jags’ first touchdown of the year.

Moore seems to be an improved player, too. He currently has a PFF grade of 73.1 and has been good for the Colts’ passing defense which is tenth against the pass. However, at 5-foot-9, Moore will be at a height disadvantage against the 6-foot-4 Chark when they line up against each other, which could set the second-year player up for another 100-yard day.