It's understood Super Rugby's governing body, SANZAR, bowed to pressure from rival coaches and is also considering rewriting guidelines to close any loopholes that would allow a senior coach to enter the field of play.

Fairfax Media revealed last week that rookie head coach Larkham had been granted SANZAR approval to maintain his role as Brumbies waterboy, given director of rugby at the Brumbies Laurie Fisher would be the man in charge from the coach's box on game day.

But it's also understood rival Super Rugby coaches contacted SANZAR this week to express concerns, given it could have opened the door for Larkham to give directions to players on the field.

International Rugby Board and SANZAR protocols specify that no head coach is allowed to run water.

SANZAR backtracked on its initial approval - which was given in November last year.

The Brumbies and Larkham will not contest the decision, saying they're happy to adhere with SANZAR's ruling. SANZAR declined to comment on Friday.

''We understand SANZAR's decision, we accept it and we're happy to work with them moving forward this season,'' Larkham said.

''We are only concerned about preparing for the start of the season and our game against the [Queensland] Reds [at Canberra Stadium on February 22].''

But the application of rules over the waterboy saga has become more farcical than the Adam Sandler comedy hit of the same name.

The ban applies to ''head coaches'', but it's understood the Super Rugby guidelines could be changed in the future to include a director of rugby role in the rule.

Larkham has been the Brumbies' waterboy for the past three years and had stated his desire to retain the role.

The former Australian Wallabies and Brumbies play-maker, who retired from playing Super Rugby in 2007, felt he got a better feel for the game on the field.

''You miss out on the emotion and communication if you're up in a coach's box,'' Larkham said last weekend.

''I think getting on and giving messages yourself is quite important. This way we can get two perspectives on the game and I can get on the field. I'm looking forward to that again.''

It's understood the Brumbies are still seeking clarity on where their coaches will be allowed to be during matches.

In the past, Wallabies mentor Ewen McKenzie was told by officials to return to the coach's box when he was spotted on the sideline as coach of the Reds.

Larkham has taken over as Brumbies head coach this season from former World Cup-winning mentor Jake White.

The Brumbies will play their final official trial match against an ACT XV at Viking Park on Saturday night.