User blog comment:FairyRaven/Fairy Tail Chapter 425: Sabertooth X792, Review and Commentary/@comment-121.54.58.243-20150323122032/@comment-7418318-20150323175244

He's trying to keep it "in the family". He intends to just deal with the matter himself before Frosch ever get's into danger.

F-Rogue and what happened to present Rogue during his fight against Gajeel have proofen that Rogue isn't fully stable, so upsetting him with news of Frosch's impeding death isn't something to be done lightly.