Coach Rob Mendez speeds around on the football field with intensity and admits he demands a lot of his athletes.
"There's no excuses on my football field," Coach Rob told NBC Bay Area. "If I can be out here, then there's no excuse for them to be pouting or anything like that."
Coach Rob, as his players call him, was born without arms or legs, but the 21-year-old never uses that as an excuse so the bar is high on his field.
"He's throwing a bad ball on purpose is what you said?" asks Mendez of one of his receivers who dropped a ball during practice this week. "Don't blame the quarterback. Once we start pointing fingers, it's downhill from there."
Coach Rob is the offensive coordinator for the San Jose 49ers, a Pop Warner team in the South Bay.
"There's something about him that makes you want to run the plays harder," said quarterback Rene Martinez.
The other quarterback on the team, Albert Ramirez, said, "I think he's a good guy. He's an inspiration."
Even when he's yelling.
After one pass, Coach Rob told Ramirez , "That was a horrible ball, horrible ball."
"He really understands the game and understands the kids. He's something to look forward to every time we come out here," said head coach John Loera.
Coach Rob also issues compliments when they're merited, but he knows he has to light a fire in his players, to motivate them.
"We're just going to be practicing our routes guys," Coach Rob told his offense. "Because you guys did not run through your routes fully at all the whole game. I'm calling you out. Calling you guys out."
It was dark when practice ended for the kids, most of them low income from East San Jose.
"What I hate is self pity," said Mendez. "Self pity really chaps my butt. "