Players are back in Allen Park today for the start of the offseason training program. The players being back in the building makes it seem like football is right around the corner.

The offseason training program takes place over the course of the next three months, and is designed to help get the players and coaches ready for the start of training camp this summer.

Here are five things to watch out for in the coming weeks as the Lions get started on their 2019 campaign:

1. PHASES EXPLAINED

The voluntary offseason training program takes place over the course of the next nine weeks and consists of three phases.

Phase One: The first two weeks of the program with activities limited to strength and conditioning and physical rehabilitation only.

Phase Two: The next three weeks of the program. On-field workouts may include individual player instruction and drills as well as team practice conducted on a "separates" basis. No live contact or team offense vs. team defense drills are permitted.

Phase Three: The next four weeks of the program. Teams may conduct a total of 10 days of organized team practice activity, or "OTAs". No live contact is permitted, but 7-on-7, 9-on-7, and 11-on-11 drills are allowed.

2. INSTALLATION OF NEW OFFENSE

The second phase of the offseason training program is always critical as it's the first time since the end of last season coaches get to really work with players. For the offense, it will be the beginning of the installation of new offensive coordinator Darrell Bevell's scheme.

Bevell and offensive line coach Jeff Davidson have worked closely to try and build this scheme to maximize the strengths of the players on the roster. Head coach Matt Patricia expects it to be adaptable, much like his defense.

"It'll grow, it'll develop, it'll move, it'll shift and whatever it looks like in the spring will be different than training camp and what it looks like in September will be different than what it looks like in December," Patricia said.

"I'll just be real excited when we get to that point where we can then have the conversation with the players, because to be honest with you, that's the best part. When you sit down with the players and get an opportunity eventually here to sit down with a Matt Stafford and say, 'Hey, what do you like? What works for you? These players on our team do this really well. How do we fit these pieces together?

"It'll definitely be something for us on the offensive side of the ball that'll be a continuing process through the spring because the most important key of it will be getting our players back."

3. BIG LEAPS IN PRODUCTION

The offseason training program is more about individual development and installation than it is competition. The competition part of the roster building begins in earnest come training camp.

In the spring, coaches want to see what the players have been doing over the last few months since the end of the season to get better. Every player leaves the building in January having met with the coaches. They're given an evaluation of their season with a list of things coaches want to see them do better. Who went to work? Who didn't?

Coaches will look for the second-year players to take a big leap. Those guys had a true offseason to work on their craft. Players like Frank Ragnow, Kerryon Johnson, Tracy Walker and Da'Shawn Hand, in particular, should be expected to have significant roles for this team in their second season.

General manager Bob Quinn is hoping third-year cornerback Teez Tabor takes a leap in his third season and becomes the player he thought he could be when he drafted him in the second round a couple seasons ago. Does he come back ready to be a factor in Patricia's defense?

4. DEFENSIVE MATURATION

Patricia and defensive coordinator Paul Pasqualoni were in the same spot last year that Bevell is in this spring – installing a new scheme.

Detroit's defensive scheme is complicated and multiple. It took some time to fully install it, and for the players to feel comfortable in it. But the end results were pretty good. Detroit was good defensively against some of the best offenses in the league last year, and finished in the top 10 in the league in total defense (10th), pass defense (8th) and run defense (10th).

Now look for Patricia and Pasqualoni to fine-tune some of the details and get into some of intricacies of this scheme. Detroit returns eight starters on defense and added top free agent defensive end Trey Flowers and cornerback Justin Coleman to the mix, both of whom have experience in a similar scheme.

The defense should hit the ground running in the spring. I expect it to be pretty formidable this season.

5. PARTICIPATION

It's worth noting that the offseason training program is voluntary and participation isn't required. The only thing required by the team and the league is participation in the June minicamp.

That being said, the Lions had nearly 100 percent participation in the program last year in Patricia's first season as head coach. I expect a similar turnout this year. There will be things that come up over the spring that players have to tend to, but this is an important time of year to get the installation down and prepare bodies for the rigors of a 16-game NFL season.

The Lions need to take a big step forward from last year's 6-10 season, and that starts today in Allen Park.