Rookie international props Jack McGrath and Martin Moore have turned Ireland scrummaging sessions into a fearsome contest, according to Rory Best.
Leinster duo McGrath and Moore are primed for bench duty in Sunday's RBS 6 Nations opener against Scotland in Dublin.
Fast-developing tighthead Moore is expected to win his first cap as a replacement, with experienced campaigners Cian Healy and Mike Ross Ireland's starting props.
Ulster hooker Best will win his 71st cap, with Sean Cronin among the replacements and McGrath in line for just his fourth international outing if he joins the fray.
Best admitted Ireland's forwards have sunk their teeth into some testing scrum tussles in training at their Carton House base in Six Nations preparations.
"When we're training in the scrum now, if you don't get it right you're going to get done, which is exactly what it will be like on Sunday," said 31-year-old Best.
"And that's important. It obviously brings competition for places, which is good for everyone, with these young guys coming through.
"There's some real competition in training there now. From that side of things it's great to see, especially with their age profile too, these guys are young and have a fantastic future ahead of them.
"It's important that they know getting into the extended squad is just step one.
"And then getting into the match-day squad is step two, and then you've got to be looking to start and push to better yourself every time.
"That's the attitude they will adapt, they've already given that impression, and it's great for the squad.
"Competition for places drives everyone on and hopefully raises standards across the board."
* England will give debuts to outside centre Luther Burrell and wing Jack Nowell in tomorrow's RBS 6 Nations opener against France.
Burrell has impressed throughout the season for Northampton, where he has been playing in the No 12 jersey, and starts ahead of Brad Barritt who is included on the bench.
Nowell, the tackle-busting Exeter wing, has benefited from injuries to Marland Yarde and Christian Wade to seize the No 14 jersey from the axed Chris Ashton.
Team: M Brown (Harlequins); J Nowell (Exeter), L Burrell (Northampton), B Twelvetrees (Gloucester), J May (Gloucester); O Farrell (Saracens), D Care (Harlequins); J Marler (Harlequins), D Hartley (Northampton), D Cole (Leicester), J Launchbury (Wasps), C Lawes (Northampton), T Wood (Northampton), C Robshaw (Harlequins, capt), B Vunipola (Saracens). Replacements: T Youngs (Leicester), M Vunipola (Saracens), H Thomas (Sale), D Attwood (Bath), B Morgan (Gloucester), L Dickson (Northampton), B Barritt (Saracens), A Goode (Saracens).