sand lot(1)
n. A field, vacant lot, or other open place used as a sports playing field, usually by younger teams or by amateurs who can't afford to use anything better.
Rogers Hornsby, who was National League baseball batting champion six times, first started playing on Texas sand lots.

[TahlilGaran] English Idioms Dictionary ▲

sand-lot(2)
adj. Of the kind seen on sand lots; not professional.
The professional football team was so confused by their opponents' fast play that they acted like a bunch of sand-lot amateurs.

[TahlilGaran] English Idioms Dictionary ▲