The on-field workouts begin Thursday at the NFL's scouting combine inside Lucas Oil Stadium in Indianapolis.

A look at what you need to know:

The workouts: 7-11 p.m. ET (NFL Network), quarterbacks, wide receivers and tight ends do the vertical jump, broad jump, 40-yard dash, shuttle drills and position drills.

And ...: The offensive linemen and running backs will do bench press; defensive linemen and linebackers have their medical exams; and defensive backs will be measured and weighed and go through psychological testing.

The record holders: Former University of Washington wide receiver John Ross -- now with the Cincinnati Bengals -- ran a 4.22-second 40-yard dash in 2017, which is considered the record in the combine's electronic timing format that began in 1999. Bo Jackson's hand-timed 4.12 in 1986 has long been considered the best combine 40 time.

At the top of the board: LSU's Joe Burrow and Alabama's Tua Tagovailoa, the top quarterbacks in the draft, will not work out at the combine. One of the top tight ends -- LSU's Thaddeus Moss -- also will not work out. A deep group of receivers is expected to rule the day, as scouts say they're prepared to see plenty of speed and potential for immediate impact in the league.

Who can really help themselves: The "other" quarterbacks -- those not named Burrow or Tagovailoa -- have a chance to get attention. Utah State's Jordan Love has compared his own skill set to that of Patrick Mahomes and is trying to convince personnel executives he can add consistency and better decision-making along with what many consider the strongest arm in the draft class. A player such as Georgia's Jake Fromm, who has shown quality decision-making with 42 college starts, has to continue to prove he has enough arm strength to do the job as a pro. All of the quarterbacks in Indy will throw to what is being called the deepest, most talented group of receivers in years.

Don't miss: Tight end Adam Trautman was a lightly recruited prep quarterback when he went to Dayton, but in an NFL looking for pass-catchers who can put pressure on a defense all over the field, he has a growing fan club. Baylor's Denzel Mims can also add to his strong week at the Senior Bowl in a crowded group of wideouts. Former Oklahoma/Alabama quarterback Jalen Hurts has done nothing but win games and pile up touchdowns, and yet he is still trying to convince some in the league about what he can do behind center. He'll get another chance Thursday.

More on the combine: