WARY coach Michael Cheika is relishing a “war” on the field against Argentina and a week of respectful byplay with the canny Pumas chief who knows the Wallabies as well as his own team.

Argentinian coach Mario Ledesma sat in Wallabies’ planning meetings and was a Cheika confidante for three seasons (2015-17) when he was the team’s respected forwards boss.

The Ledesma stamp is already obvious with the extra poise he gave the Jaguares in Super Rugby when he guided four wins away from home in Australia and New Zealand where Argentinian sides are often a shadow of the force they are on home soil.

“Without doubt, Mario was a very important part of the development of this (Wallabies) team,” Cheika said.

“He’s always going to be an influence on us and us on him.

“This week’s going to be a bit different. You always come up (coaching) against guys you know along the way and there’s a bit of hedging and mind games but not this week.

“We’re too close, we’re family (with previous stints together at Stade Francais in Paris and the Waratahs)

“It’s like brothers going at it. Once the whistle goes it’ll be war but it’ll be respect before.”

Cheika came unstuck 3-0 in 2016 when former Randwick pal Eddie Jones came visiting with England and brought his verbal boxing gloves.

Mail for Ledesma still landed occasionally at the Rugby Australia offices in Sydney until recently.

“I’m sure we’ll catch up during the week and I’ve got some mail that’s stacked up at home I have to give him,” Cheika said.

Cheika knows the challenge of the Pumas, who pressed the All Blacks at times in a 46-24 loss in Nelson last Saturday and toppled the Springboks in Mendoza last month.

“I watched their Test against the All Blacks and we know they are on an upward curve … they looked sharp with their attack, their counter-attacks and we know how good their off-load game is,” Cheika said as a warning.

Cheika laughed when it was suggested the Pumas might use a Wallabies move against them that Ledesma had borrowed.

“Everyone is ripping everything off everybody in this game with people watching footage. No one owns that intellectual property,” Cheika said.

“I’m sure we’ve influenced him as his influence is on us.”