what to do about underachivers?

1: If they make MISTAKES - tell them at least to make the mistake going 100 MPH. YOUR coaching & many Reps should correct mistakes.

2: If they LOAF - sit their behinds on the pines!

What other choice is there?

all good stuff thank you guys. As for my two players, one is a senior who had not got much playing time at LB. He was terrible there despite his gifts. So he is now a slightly undersized DE in a 44. He gets pushed around some, but it is definetly his best placment. He kills in practice, but just doesnt show up for the game. He looks like he just saw a gost, deer in the head lights every game. He still plays ok, but just avearge, with some really bad plays mixed in.
The other is a DB/WR junior who was moved to OLB out of nessessity. I am moving him back to DB. He thinks he is trying his best, but he just 1/2 asses. I think he is scarred of going all out and messing up. He's not lazy, just scared I think.
Funny thing is they both were a QB at some point with great hopes of being the one to lead the team... they blew that quick.

I am going to bring them both in and talk with them about taking a different approach to game night. I gotta get somthing out of these kids. Were a small school with not too many other options.