Huddersfield captain Chris Thorman is "extremely doubtful" for the Challenge Cup final with a hamstring injury and is undergoing acupuncture to get fit.
Stuart Donlan (quad strain) and Martin Aspinwall (groin) are also doubts but Brad Drew should recover from a calf strain and Paul Reilly is fit.
St Helens have a full squad to choose from, leaving coach Daniel Anderson with some tough selection dilemmas.
Vinnie Anderson and Nick Fozzard are tipped to be the unlucky ones left out.
Anderson is a regular New Zealand international, while Fozzard won his first Great Britian cap in last autumn's Tri-Nations.
"I'll go with what I think is the best balance for the game and the best team to play against Huddersfield," Anderson said.
"There will be players left out who will be perceived as having no reason not to play."
Thorman is expected to be given every chance to prove his fitness right up until Saturday morning, even if coach Jon Sharp insists he will not gamble in such a big match.
"History tells us if you pick players who are injured in a Cup final it can come back to bite you," he said.
Leeds gambled on the fitness of Keith Senior in last year's final and were forced to substitute him at half-time.
With Huddersfield's other specialist stand-off, Paul March, out for the season with a serious knee injury and another natural replacement, Kevin Brown, ineligible, 19-year-old Tom Hemingway may be called upon.
He has only made six Super League appearances but impressed Thorman during their 14-10 league defeat at Wigan.
"My disappointment, if I don't play, is going to be another guy's opportunity to make some history," Thorman said.
"Tom is a very talented player and had a good game on Friday to shake the cobwebs off. I'm sure he would do a good job."
If Hemingway plays, it will rekindle memories of Peter Ramsden, who won the Lance Todd Trophy on his 19th birthday after scoring two tries as Huddersfield beat Saints 15-10 in the 1953 final, the last time they won the Cup.
The Giants will start rank 5-1 outsiders on Saturday in their first final for 44 years, but aim to emulate the likes of Sheffield Eagles, against Wigan in 1998, and Featherstone, against Hull in 1983, and upset strong favourites.
They can at least draw inspiration from being the first team to beat Saints this season in May, even if their last meeting three weeks ended in a 56-8 hiding.
Martin Offiah, who played in four Challenge Cup finals for Wigan and twice won the Lance Todd Trophy as man-of-the-match, will present the trophy to the winners at Twickenham.
Saints scrum-half Sean Long is aiming to become the first player to win the Lance Todd Trophy three times, having been man-of-the-match in 2001 and 2004.
COVERAGE Saturday 26 August 2006 Kick-off: 1445 BST (2345 AEST, 0145 Sunday NZST)
Live TV coverage on BBC One (UK) and Sky Sport 3 (NZ). Live radio coverage on BBC Five Live (UK) and through www.bbc.co.uk
Delayed TV coverage on Fox Sports 1 (Aus) at 1:00am AEST Sunday 27th August, one-hour highlights at 9:00pm AEST Sunday 27th August.
SAINTS' ROUTE TO THE FINAL 4th round: v Doncaster (h) 56-6 5th round: v Bradford (h) 42-18 Quarter final: v Catalans (h) 56-10 Semis: v Hull KR (n) 50-0
GIANTS' ROUTE TO THE FINAL 4th round: v Halifax (a) 40-8 5th round: v York (h) 38-4 Quarter final: v Salford (h) 44-14 Semis: v Leeds (n) 30-12
Huddersfield Giants 20-man squad: Reilly, Aspinwall, De Vere, Donlan, Thorman, Paul, Crabtree, Drew, Gannon, Nero, Snitch, Wild, Jones, Jackson, Smith, McDonald, Raleigh, Gardner, Hemingway, Mason.
St Helens 20-man squad: Wellens, Gardner, Lyon, Talau, Meli, Pryce, Long, Cayless, Cunningham, Fozzard, Gilmour, Wilkin, Sculthorpe, Roby, Hooper, P Anderson, V Anderson, Graham, Hardman, Fa�asavalu.
Referee: R Silverwood