The Lions defensive coach Phil Larder has picked out the Wallaby half backs as the danger men this Saturday and defended the Lions against allegations of illegal tackling.

Echoing manager Donal Lenihan earlier in the week, he described the tackle by Nathan Grey that ended Richard Hill's tour as a "blatant elbow" and a potentially lethal challenge that would have resulted in a six week ban in his previous sport, rugby league.

And, amid accusations that the Lions illegally targeted Larkham in last week's second Test in Melbourne, he vowed they would do the same this week and, as last Saturday, that it would be done within the laws of the game.

"Steve Larkham and George Gregan are two key players for their team, the guys who call the shots, so we've got to put them under as much pressure as possible, but it will be legal. We have to close down their space and the longer Steve Larkham is on the floor, the better it is for us."

He vehemently denied the late tackles by Scott Quinnell and Rob Henderson on Larkham, following clearing kicks in Melbourne, were in fact illegal. And he hit out at Wallaby centre Grey's challenge that left England openside flanker Richard Hill concussed and out of Saturday's Test.

"It was a blatant hit with the elbow to the chin. Hill went down for the count," he said. "Use of the elbow is lethal and if I go back to my league days he would have been out six weeks." - Grey escaped any disciplinary action.

Larkham's latest injury, that is threatening to rule him out of the third Test, came when he tackled Lions centre Brian O'Driscoll in the first five minutes. But he said he expected to be targeted by defences during games.

"I think it's part of the game now," he said. "A lot of sides try to shut the playmaker down. It's something we expect and plan to negotiate in games."

Meanwhile Larder, said he did not think the decider, at Stadium Australia in Sydney, would be a free-scoring thriller. "Defence will win the game," he said. "And we are playing against the best defensive team in the world."

The Wallabies will delay naming their team until Thursday - as the Lions are well aware under IRB rules the team must be announced at least 48 hours before the match - giving Larkham as much time as possible to recover.

In training this week Larkham's arm seized up and he found it difficult to pass or run. "It feels kind of weird and frustrating being in doubt every week but it's something you have to deal with," he said.