In the second of a four-part series leading up to the NFL Draft April 30-May 2, The Post takes a look at offensive linemen, defensive tackels and pass rushers. Next week: linebackers and defensive backs.

Leonard Williams didn’t start playing football until high school, but that wasn’t by choice.

The best defensive tackle in this year’s NFL Draft — and by many accounts the best player available, period — was considered too big and too good as a middle schooler for Pop Warner officials in Florida to let him in.

Williams was already 210 pounds in the seventh grade, well above the individual weight limit.

“I couldn’t just cut 30 pounds to play football,” the USC product told reporters at the scouting combine last month. “As a kid, it made me really sad because that’s a boy’s dream to play football. To not be able to do that was hard. But my dad told me it was going to pay off one day.”

That day Williams’ father predicted is about to arrive, as Williams has scouts in a tizzy with his prodigious skills and appears likely to be the second player taken in the April 30-May 2 draft in Chicago.

Observers don’t hold back when talking about the 6-foot-5, 300-pounder, with NFL Network draft analyst Charles Davis labeling him “a Hall of Fame talent” and USC athletic director Pat Haden — a former NFL quarterback — saying Williams was one of the five best Trojans he had seen in more than 40 years being around the school.

https://twitter.com/ADHadenUSC/status/549716178336088064

“He is that good,” Haden wrote on Twitter.

Despite the late start to his football career, Williams is no late bloomer. He chose USC over Alabama and Florida and arrived on campus with huge expectations, which Williams promptly met by emerging as a Freshman All-American selection.

Though the USC program as a whole struggled in Williams’ three seasons (he declared for the draft after his junior season), Williams was as reliable as a rock in the middle of the Trojans’ defensive front.

Thanks in part to NCAA sanctions stemming from the Reggie Bush case, USC cycled through three coaches — Lane Kiffin, Ed Orgeron and Steve Sarkisian — during Williams’ stint and lost at least four games all three years.

But Williams, a reliable source of pride throughout, racked up 21 sacks and totaled 36 tackles for lost yardage in his career. He also emerged as a team leader with his buoyant, charismatic personality.

Williams credits that to having to grow up quickly, considering his father eventually went to prison and his mother moved around frequently while trying to raise a family of five. At one point,

Williams and his siblings even lived briefly in a homeless shelter.

That rough background is one of the main reasons Williams decided to turn pro after just three seasons. He already has declared he will buy his mother a house with money from his first NFL contract.

“It’s going to mean a lot to be able to take care of her,” Williams told reporters at the combine. “My mom was a strong single parent. She took care of five children who were all my size, so I’m sure it was hard for her to put a lot of food on the table. She’s a strong woman, so hopefully one day I’ll be able to repay her.”

Williams is in such high demand because he is so versatile, which is rare for an interior defensive lineman. He appears best suited to defensive end in a 3-4 scheme but is athletic enough, even at 300 pounds, to be a 4-3 end.

Scouts compare him to former Patriots great Richard Seymour and perennial Vikings All-Pro Kevin Williams. For his part, Leonard Williams is just ready to get started in a league that — unlike the Pop Warner outfit of his youth — is eagerly awaiting his arrival.

“I just see myself playing for any [defensive line] wherever they want to line me up,” Williams said at the combine. “I’ll just try my hardest to learn that position and learn to my best ability and play the best I can.”

Post NFL writer Bart Hubbuch ranks the top offensive linemen, defensive tackles and edge pass rushers in the April 30-May 2 draft:

No          Name                             Pos.           School            Ht.            Wt.

1.          Brandon Scherff        OT             Iowa            6-5              320

Best of a middling class but dogged by concerns about arm length and pass blocking.

2.           Andrus Peat*              OT           Stanford       6-7             315

Big, durable and reliable blocker who also has a noted mean streak.

3.          Cameron Erving          C                Florida State   6-6          315

Converted defender was a rock for the Seminoles the past two seasons.

4.           La’el Collins               OT            LSU              6-5              305

Big-framed blocker with a nasty side who missed one start his final three seasons.

5.           Ereck Flowers*          OT          Miami            6-6               330

Huge prospect with good athleticism for his size and is known as a team leader.
underclassman

Jake Fisher, OT, Oregon: A durable and technically sound blocker who has looked good in offseason workouts and can play tackle or guard.

T.J. Clemmings, OT, Pittsburgh: Inexperience, struggles at the Senior Bowl and mediocre workouts eliminated top-10 buzz.

Ali Marpet, G, Hobart: Athletic Division III prospect who made the most of his time in front of scouts at the Senior Bowl, then the combine.

No.          Name                                  School                  Ht.              Wt.

1.               Leonard Williams       USC                       6-5               300

Relentless, durable and versatile defender looks like a lock to go No. 2 overall.

2.               Danny Shelton         Washington              6-2            340

Wide body who never missed a game, but there are worries about his motor.

3.              Malcolm Brown*        Texas                        6-3               320

Mature and dependable player who is considered the draft’s best run-stuffer.

4.              Arik Armstead*           Oregon                    6-7             290

Possesses ideal size and frame for the position, but injuries are a concern.

5.            Jordan Phillips*           Oklahoma        6-5               320

Scouts love his size and athletic skills but hate his lack of maturity and lazy streaks.

*underclassman

Xavier Cooper, Washington State: This 6-foot-3, 290-pound prospect was well under the radar until his 4.86 40 at the combine was the best at the position.
DROPPING FAST

Eddie Goldman, Florida State: Still likely to go in the first three rounds, but Goldman hasn’t helped himself with injuries and a lackluster pro day.

Christian Covington, Rice: A tenacious defender and son of a Canadian Football Hall of Famer (father Grover was a standout for Hamilton from 1981-91).

No.                      Name                             School                  Ht.                 Wt.

1.                    Dante Fowler Jr.        Florida                  6-3                 260

Smart, productive player with a great first step who never misses a game.

2.                      Randy Gregory*        Nebraska            6-5                  235

Stock has been hurt by his lack of bulk and a positive combine marijuana test.

3.                        Shane Ray*             Missouri               6-3                   245

Terrific athlete (4.5 40 at the combine) who had 14 sacks as a junior last season.

4.                    Hau’Oli Kikaha           Washington        6-2                    255

Had 32 sacks the past two seasons and led the nation in that category in 2014.

5.                       Bud Dupree                Kentucky           6-4                    270

Has prototypical size and is a top athlete, but poor instincts are a concern.

*underclassman

Vic Beasley, Clemson: No questioning his size or strength anymore after a sensational combine zoomed him near the top of his class at the position.

Shaq Thompson, Washington: He failed to live up to the hype at the combine, posting underwhelming numbers that have sent his stock plummeting.

Edmond Robinson, Newberry: Scouts like this athletic prospect’s chances of becoming just the second player ever drafted from his school.