The preseason slate of training camp kicks off tonight for the Lions against the New York Giants at MetLife Stadium in both teams' preseason opener. While we aren't expected to see quarterback Jared Goff and many of the other starters, that doesn't mean there isn't a lot to keep an eye on tonight as playing roles and roster spots continue to be up for grabs.

“Certainly, some of the guys we know we're going to count on during the season, I don't see them necessarily playing and if they do, not very many reps,” Lions head coach Dan Campbell said this week. “But our young guys are going to get a lot of these, and developmental players are going to get a ton of these reps.”

Here are five things I'll be watching out for in tonight's contest:

Backup quarterback competition

Nate Sudfeld and Hendon Hooker are likely to get a half each tonight as they continue to compete to be Goff's backup come the regular season. This will be the first game action for Hooker in almost two years since he suffered a torn ACL while on a Heisman Trophy run at Tennessee. He needs to run a smooth operation getting the calls in and working efficiently.

“He just needs reps. And it doesn't matter if it's us or it's them or it's a game, he just needs reps and reps and reps and he goes to bed and he needs reps and he wakes up and he needs reps,” Campbell said this week of Hooker. “Any time he can be out there and run the offense and function it's going to be good for him.”

Sudfeld, who tore an ACL in the preseason last year, has looked pretty good in training camp so far and will be looking for more of the same tonight.

Depth at wide receiver

We know Amon-Ra St. Brown, Jameson Williams and Kalif Raymond are in at wide receiver, but who will be No. 4 and possibly No. 5 on the roster out of camp?

As it stands right now through three weeks of training camp practice including two joint practices this week with the Giants, Daurice Fountain and Kaden Davis have looked the best of all the receivers competing for those roles. Donovan Peoples-Jones, who the Lions traded for at the deadline last season, is also in the mix, though Campbell said last week he's looking for more from Peoples-Jones. He and everyone else competing for roles and roster spots at receiver will have an opportunity tonight to make a big impression on a big stage.

No. 3 running back spot

Kind of like we talked about at receiver, Detroit is still trying to figure out who will be the No. 3 running back behind David Montgomery and Jahmyr Gibbs. Craig Reynolds has held down that role the last couple years and has been good, but rookie Sione Vaki and veteran Jermar Jefferson are looking to push him.

Reynolds has looked really good in camp, but so has Jefferson. He's taken a step forward in his development this training camp and Campbell said last week Jefferson is in a really good spot right now. Reynolds, Jefferson, Vaki and the rest of the backs competing for roster spots are expected to get a lot of work tonight. Who can put themselves ahead of the pack?

Defensive line

We aren't expected to see Aidan Hutchinson, Alim McNeill, Marcus Davenport and some of Detroit's other main contributors upfront along the defensive line, but we will get our first look at just how deep that unit could be. I'll have a particularly close eye on the edge players. Detroit's looking for more production opposite Hutchinson this season and there are some players who have flashed in camp so far. It will be interesting to see if Levi Onwuzurike plays tonight. He's been great in camp playing both inside and outside. If he doesn't play, we know where he stands as an expected contributor. If he does play even limited reps, keep an eye on him. Same goes for players like James Houston, Mitchell Agude, Mekhi Wingo and Mathieu Betts.

Jake Bates' Preseason Debut: The New Kickoff Rules Take Effect

Bates played in a preseason game with Houston last year and was 2-for-3 kicking extra points before he was released the following week. He then went to the UFL and had a nice year, which earned him a chance in Detroit in training camp.

Bates has had an up-and-down camp so far and tonight is big for him. It's expected to be rainy and windy in New Jersey for tonight's game, so it will be a good test for Bates. We all know he's got a big leg, but can he consistently put it between the uprights on extra points and shorter field goals?

It will also be Detroit's first game with the new kickoff rules. Bates' ability to place the ball where special teams coordinator Dave Fipp wants is part of the evaluation too.

The Lions and Giants are coming off a week of joint training camp practice that was marred by fights, including a couple of incidents that resulted in fines for both teams. The NFL fined each team $200,000 for the scuffles, and it's a sign that the Lions and Giants are taking these preseason games very seriously. It's going to be a great way to end the first week of preseason and I'm excited to see what we can learn from the young guys on both sides of the ball.