It was most likely lidocaine with epinephrine. The lido would numb the pain and the epi would decrease blood flow so that the numbing effect would last longer. Steroids would not be effective "sideline drugs" because they have a very slow onset but a long duration of action. Sodium channel blocking anesthetics, on the other hand, work very quickly and have a short duration, hence the need for the epinephrine slow down the washout time.

Without strife, your victory has no meaning.
Without strife, you do not advance.
Without strife, there is only stagnation.

Because these are High School kids and not professionals getting paid millions of dollars!!!
LFC
NYK
U CANT C ME
10 YEARS STRONG

Well I thought doing that made the coach terrible, but if it's used in lots of sports on lots of players and no big deal, then well, what's the big deal for the coach, why does that make him so terrible?

Semen was in that needle

Cortisone. It's used all the time in almost every sport.

There are stories from the past few seasons about NFL players getting cortisone shots at halftime, then returning to the game as if nothing happened. It might take a little time for it to kick in, but it could someone back in the game.
"If I'm wrong, I'll pay for it. But if I'm right you're gonna hear about it."

Novacaine or Lidocaine.
Pain masking / reducing along with an anti-inflammatory to reduce swelling
Director Vance I am sure you are shocked and appalled at that"

I Know there is a legal non steroid teams in nfl give players if they are playing injured that makes them feel little to no pain of the injury they are playing through im just not sure what it is called.

Most likely it was a cortisone injection. Cortisone is an anti-inflammatory medication, but in real life I don't think it would work fast enough to allow the kid to play without pain in the 2nd half.