It is quite clearly not an, It would be
Let's make a hire.
Unless we speak different languages of course, which in that case I still don't think it's correct.
An is used if the first sound coming out of it is a vowel.
A is used if the first sound coming out is a consonant.
Which in our case...
oh. i think i get that quote.
1st base,
2nd base,
3rd base,
home
it's just a way of saying we're gonna borderline fuck to make it to the bottom of the ninth.
huh.