Saints arrive at Wheldon Road as the only remaining side to boast a 100 per cent winning record after the opening six rounds of the competition.
Castleford, in third, are not far behind, having lost only once, when a decimated squad fell just short at Warrington Wolves.
Loose-forward Milner missed that contest as did international colleague Oli Holmes but both are fit and firing again after returning in Sunday’s win over Salford Red Devils.
He said: “Saints are setting the benchmark at the minute and they’ve been very consistent over the last two years.
“So it’s going to be a massive challenge for us – the biggest we’ve had this year – but it’s one the boys are certainly looking forward to. It’s a statement game for us. To knock them off, we’ll have to be really good but, if we can come away with the two points, it would be massive.
“It will show where we’re at as a team. The game is being marketed as Classy Cas v the Entertainers, which it is. Both teams like to play attractive football.”
Among myriad threats, Saints have an all-England front-row in powerful props Alex Walmsley and Luke Thompson plus irrepressible hooker James Roby, the latter two being players Milner knows well after making his international bow last autumn.
“It is an international front-row,” he said.
“James Roby is a massive player for them and he’s got those two big front-rowers to play off the back of. It’s going to be important we get the better of their pack.
“We’ve spent all week looking at their games. We’ve got a plan and it’s up to us the execute it.”
In terms of getting the better of Saints’ pack, Daryl Powell’s side’s chances are enhanced tonight by the return of Australian prop Grant Millington after a two-game ban.
They will need the 32-year-old’s experience, leadership and offload ability if they are to ruin Saints’ proud record.
“Millo is a fantastic player who gives us a different dimension; we’ve missed him,” added Milner.