In American football, there is such a thing as an ineligible (pass) receiver. That is, a "lineman" (center, guard, tackle) is not allowed to catch forward passes. Are they similarly prohibited from running with the ball? I can see two cases:
1) A "back" (or pass receiver) drops or fumbles the ball, a lineman picks it up and runs with it.
2) The quarterback (or runner) hands the ball to a lineman.
I see the second happening in the case of a "quarterback sneak," that is, the quarterback allows the center to keep the ball and "plunge" for short yardage. Does this mean that a runner can hand the ball to a lineman if it is convenient? Why is this not done occasionally to "mix things up" if it is allowed? Or is such "mixing things up" something rules are designed to prevent?