WINGMAN Tommy Makinson suffered a re-occurrence of the foot injury that kept him out the past two weeks.
The club had taken the precaution of keeping the former Golden Boot out an extra week and he had come through well in training.
But he pulled up in the opening moments of Friday's Challenge Cup win over Huddersfield.
Coach Kristian Woolf said: "I think it is the same injury.
"There are no questions of bringing him back too early as he has trained fully for the last week and had has done everything asked of him.
"We gave him an extra week off but obviously he has a bit of as drama and we need to have a good look at it and figure out what we are going to do with it."
Saints also lost Louie McCarthy-Scarsbrook with a head knock - which bore similarities to the quarter finals last year when they lost two men and were knocked out of the cup.
"If you remember last year in the quarter finals we lost two players in that game as well and could not quite overcome that that day.
"We have got the result today and we live to fight another day," said Woolf.
Woolf gave a post-match update on McCarthy-Scarsbrook.
"He was fine at half time and had recovered really well. It was more a fact that he stumbled at the play the ball that alerted us.
"I am not quite sure what happened there (with the incident), but I can’t understand how you end up with a bloke on report but there is no penalty," he said/
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