GM Layer and Whisper rolls

Maybe I'm overlooking something, but is it possible to force any roll from a token on the GM layer as a whisper? I recently had a situation where I rolled for the initiative of a token on the GM layer. The token ended up in the initiative tracker, invisible to the players (as intended). However, the chat still showed the dice roll, and name of the creature, which spoiled the surprise a bit. Any suggestions, via regular means or via an API script?

A script could be written to enforce this, but I am not aware of anything out of the box, or anything in the interface that would do this.

For all NPC Initiative rolles I use the Group Initiative MOD, which has a setting for not posting the rolls into chat.