Can you do this?

[Dakota]

Originally Posted by tmielke

Any rule against what I did? Penalty?

Yes. It was an illegal sub. Any sub (even on defense) must be in the lineup somewhere, and a starter and her sub cannot be in the game at the same time. You have a fair shot at getting away with this on defense, especially in the outfield, but you do run a risk if a sharp-eyed scorekeeper notices.

If your illegal sub had been involved in a play, and the opposition protested before the next pitch, your illegal sub would have been disqualified and the offense would have had the option of letting the play stand, or a do-over.