FED (ll:ru): Illegal substitution mechanic

[LilLeaguer]

[The title contains my code for a FED-based question asked by a LL umpire who would like an answer from Real Umpires(tm).]

I don't work FED games yet, but I've been trying to learn for when I'm ready to become a Real Umpire(tm). Over on the pay side, I found a series of articles by Kyle McNeely on Federation Substution. Should I consider him a proper authority? In any case, he didn't really go into the mechanics that FED umpires should use.

Take this scenario.

The Real Baseball team leads off with Tim, Alan, and Chris in the bottom of the first inning. After three innings, Real Baseball is ahead by 4 runs and their manager, Dirty Rat, announces that reserve "A" will go into the field, replacing Chris.

Unfortunately, the Small Balls stage a comeback and are actually leading going into the bottom of the sixth. After Tim strikes out, Chris walks out to the plate and announces to the umpire, Big Dog, that he is coming back into the game. Dog confirms this with Rat, who signals his approval.

As Mr. Dog strikes his second line through "A" on his lineup card, he notices the problem: Alan should be up now.

What does Big Dog do?

-LL