[waltjp]

Maybe next year's rule book will clarify this - but this is what I'm thinking.

The 11th player left because he thought he had been replace. Upon reaching the sideline he learned that he had not been replaced so he returns to the field. I think we all agree that this is legal.

As Thomas said earlier, there are 2 questions here.

First, does he have to come inside the 9-yard marks to make himself legal or did he already do that before leaving his huddle?

Second, if he does have to re-establish himself but does not do so is he an eligible receiver?

In my opinion he does not have to come back inside the 9-yard marks. I think he already met this requirement when he was in the huddle at the RFP. (I don't necessarily like this but I don't see the rule that says it's wrong.) The rule says a player must be momentarily inside the marks after the ready for play. he met that requirement. His going to the sideline and returning does not change his status as a player. We know it's not an illegal substitution. It's not illegal participation.

But to play devil's advocate, if he does have to come back inside the marks and fails to do so I think he's still an eligible receiver as shown in the Redding's example. Their situation covers a player who remained outside the marks and then caught a pass. They don't describe this action as anything more than an illegal formation.