Matias Moroni has paid tribute to Michael Cheika for helping Argentina believe they can defeat any team in the world.
The Pumas face England at Twickenham on Sunday, with the visitors keen to build on a southern hemisphere Rugby Championship where they defeated both Australia and New Zealand.
Cheika took over as Argentina coach earlier this year and Newcastle back Moroni is in no doubt about the impact the Australian has had on the South Americans.
"Michael has been working with us and the most important thing is the mentality," Moroni said Thursday. "He has started to show us if we want it, we can do it."
Cheika is set to lead Argentina at next year's World Cup in France, although this week sees him coaching both the Pumas and the Lebanon side competing at the Rugby League World Cup in Britain.
He should however be completely free for Argentina duty by the weekend given outsiders Lebanon face his native Australia, a league superpower, in the quarter-finals on Friday.
In any event, Moroni added Cheika had already had a profound influence upon the Pumas' attitude.
"He has been working with us on our mentality and giving us the confidence that we have a great team and great players. It's showing in those of us playing in the Premiership and in France."
Moroni left Leicester for Premiership rivals Newcastle in pre-season, having played alongside England prop Ellis Genge, the Tigers' captain, in a title-winning campaign.
"The way he led when we played at Leicester was by doing things," said Moroni. "He talked really well also but also did his talking on the pitch and through the way he trains, the way he plays, the way he carries.
"He pushed the team to win the Premiership title last season but this weekend we are on different teams."