If a commander dies and goes to the graveyard before its owner can redirect it to the command zone, is it too late?

In Commander, when a commander would be put into a graveyard (or exile) from anywhere, its owner may instead put it into the command zone. This is governed by the Commander format rules and functions as a replacement effect under CR 614.1. Replacement effects are applied before the event actually happens — the card never truly 'lands' in the graveyard first.

Specifically, CR 614.1 explains that replacement effects modify an event as it would occur. So the game asks 'this commander would go to the graveyard — does its owner want to redirect it?' The owner makes that choice at the moment the commander would change zones, not after it has already arrived in the graveyard. There is no moment where opponents can 'catch' the card sitting in the graveyard before the choice is made.

Importantly, even if a player does not immediately announce the redirect and the card is physically placed in the graveyard by mistake, the Commander rules still allow the redirection because the replacement effect applies at the time of the zone change. A judge can back up the game state if the choice was not communicated in time during casual or competitive play.

Concrete example: Your commander Atraxa, Praetors' Voice is destroyed by Doom Blade. As state-based actions are checked and Atraxa would move to the graveyard, you choose to redirect her to the command zone instead. She never actually enters the graveyard — the replacement effect means she goes straight to the command zone, and your opponents cannot interact with her 'in the graveyard' because she was never there.

The only nuance: if a card like Leyline of the Void exiles creatures instead of sending them to the graveyard, a separate replacement effect applies, but the commander redirection can still apply to that exile event as well (you may redirect from exile to the command zone too).