Joe Schmidt fears South Africa might have recruited a World Cup quarter-final mole in Felix Jones.
Boss Schmidt lamented the Springboks appointing ex-Munster full-back and coach Jones to their World Cup set-up as "awkward" given his inside knowledge on the Ireland camp.
Jones formed part of Ireland's backroom staff for the 2017 summer tour to Japan, and head coach Schmidt admitted the 32-year-old's intimate knowledge of his side's set-up could prove costly at the fast-approaching global battle.
Ireland could well face former Munster boss Rassie Erasmus' Springboks in the quarter-finals in Japan, leaving Schmidt frustrated Jones could not be tempted to stay on home shores.
"It's an awkward situation with Felix," said Schmidt. "It's a fantastic opportunity for him to go to a World Cup with a team that are on a massive upward swing.
"It's awkward because - you don't have to be a rocket scientist - he came to Japan with us the last time, so he was right in amongst us.
"He was with us, he's seen everything that we deliver and would have a great knowledge of even the language we use in our camp, so it's awkward for us.
"There were a couple of opportunities here, but I'd be a massive fan of what Felix has got to offer in the future, and it will be a great learning experience for him.
"I just hope that we don't suffer as a consequence because he's a smart coach, he already knows a lot about us and if we do get to a quarter-final it has to be either New Zealand, South Africa or Italy that we do play against.
"That would mean he could be directly opposite us on the coaching bench."
Jones won 13 caps between 2011 and 2015, with Schmidt often insisting the reliable last line of defence would have featured far more but for the outstanding full-back Rob Kearney.
Despite Jones' extensive knowledge of Ireland's current regime, Schmidt insisted he will not be driven to any changes - even a simple switch in terminology.
Asked if he could be tempted to alter that coaching "language" he said Jones would know so well, Schmidt replied: "Not really, because things happen so fast and sometimes if you have some prior knowledge and you say 'this means that' and 'that means this', sometimes when you're fatigued you're adding clutter, and not giving clarity.
"In the end you need to be clear. So if they become too cluttered, that might be a good thing.
"I can't control what Jonesy does. Those days are gone. Once he played full-back for me and I had a little bit of influence but he's a champion player, a champion bloke and I think he's going to be a really good coach.
"I just hope he delays that by a couple of months and is pretty average for the next two months. That would be good."