Apologies for the epistle.
Would they be offsides in my original scenario, if their teammate ran ahead to put them onsides (or any of the other normal actions that puts a player back onside), before they rejoined the playing area?
Would you peep them when they re-enter the playing area (as crossref said we should) or would you allow them back onto the playing area?
I’d need to see it.
First thing is probably the easiest; are they offside? They may have no option to join in an offside position since the naughty corner and technical area (well, the pile of bags, jerseys, and water bottles by the coach) is often near the middle of the pitch. As long as they get themselves back onside without interfering with play, then all good and play on. Otherwise PK (under 10.4) for offside with mark being where I think they began to interfere, not necessarily where they joined the pitch.
It seems like not peeping the player who's re-entering allows for a potential advantage when coordinated carefully.
If they join in a way that I think is gaining an advantage then that’s also a PK (under 3.7).
So… back to the OP:
1. No, off the pitch not offside
2. No, still off the pitch.
3. If ahead of the kicker or other non-offside teammate then yes, offside. Would treat like a player getting physio attention and play has put them offside. Get back without interfering then all ok. Any interference and it’s a PK for offside.
4. Still in touch so not offside. But, if they then get in the way then it’s PK for interfering with an opponent when the ball is dead.
5. Same as 3. Unless a teammate has put them onside then yes, now offside once they re-enter but not an issue per se. I need to see them get back onside without delay, and without interfering. Otherwise PK for offside. If I suspect it’s a deliberate ploy for advantage then PK under 3.7.
That said, if another ref disagrees and thinks “yes” for points 1-3 then does it really matter? It is not an offense to be offside. It’s only an offense if they interfere with play while offside.