Les Kiss says England will pose a major threat to Ireland's hopes of a Six Nations victory in Dublin next weekend.
Ireland's defence coach warned that England's increasingly confident side could derail their bid to retain their Six Nations title on 1 March.
Kiss identified George Ford's "scary relationship" with Jonathan Joseph and Anthony Watson as an obvious threat.
"Our preparation starts with the analysis and that's been pretty scary with what they can do," Kiss stated.
Ireland and England are the Six Nations' only remaining unbeaten sides, but Kiss has denied that the winners at the Aviva Stadium will stride onwards to the title.
"If you look at that scary relationship in midfield with George Ford, and he has a relationship already with Watson and Joseph, those types of combinations seem to be coming through for them nicely.
"I think also their back row has been brilliant, James Haskell and Billy Vunipola are big threats and Chris Robshaw is excellent.
"The momentum that they give them is critical and they can take the ball deep and still make yards."
|Ireland's 2015 Six Nations matches|
|7 February||Italy 3-26 Ireland|
|14 February||Ireland 18-11 France|
|1 March||England (h)|
|14 March||Wales (a)|
|21 March||Scotland (a)|
Kiss believes Joe Schmidt's side face a tall order to contain Stuart Lancaster's side and played down speculation it could define this year's Six Nations.
"You've got to be really on your game and make sure you do hit and stick in your tackles," said Kiss.
"You've got to get them to the deck early, make them make decisions about how they load their attack.
"The analysis of it has opened our eyes to the challenge ahead and what it presents.
"With the type of competition this is, it's not going to be over until the last game, no matter what happens in the next match."
Ireland held an open training session at Connacht's Sports Ground in Galway on Wednesday, with Tommy Bowe and Keith Earls sitting out parts of the action purely to manage their workloads.
Kiss confirmed Ireland do not have any new injury concerns and moved to downplay the impact of Johnny Sexton returning to France for Racing Metro action this weekend.
The 29-year-old will face a stern examination against Clermont for his Paris club side, just a week after being clattered about the Aviva Stadium by Mathieu Bastareaud on his return after a 12-week concussion absence.
"Johnny's a pro and he'll get back and get in front of things in terms of the computers when he gets back," said Kiss.
"He'll get in front of the vision and he'll get to chat with the guys and will get in front of things really early (next week).
"Rather than being a glass half-empty it's a glass half-full situation, because Joe (Schmidt) gets a chance to work with Ian Madigan in this case for this training session."