Help Needed (Again)

[Rufus]

Had this one happen this weekend and I'm not sure how it's supposed to be handled. This happened during a tournament that was a mish-mash of Fed and local rules so I'm not so much interested in how it should have been called (i.e., criticizing the on-field decision reached), more about how it's supposed to be called in the future in case this one comes up again.

Here's the situation. A player not appearing on the lineup card checks in and plays an inning in LF. The defense gets three outs and goes into the dugout to take their at bats. They've already batted once around their order (using a continuous lineup of 11 players). The opposing coach brings the "rogue" player to the umpire's attention. What, if anything, can/should be done about it? Would appreciate both Fed and USSSA/OBR treatment.

In looking through the USSSA rulebook I found something that sort of applies but, since the player was not listed as a substitute on the lineup card, am not sure how they can become legal.

8.03.J If no announcement of a substitution is made, the substitute shall be considered as having entered the game when:
8.03.J.1 If a pitcher, he takes his place on the pitcher’s plate;
8.03.J.2 If a batter, he takes his place in the batter’s box;
8.03.J.3 If a fielder, he reaches the position usually occupied by the fielder he has replaced, and play commences;
8.03.J.4 If a runner, he takes the place of the runner he has replaced.

Rule 8.03.J Comment: Any play made by, or on, any above mentioned unannounced substitution shall be legal.