Saints could be without Shannon McDonnell for several months - leaving Keiron Cunningham with a massive headache at full-back.
McDonnell, signed on a short-term deal, was the club’s only specialist full-back following injuries to Jonny Lomax and Paul Wellens.
He went off during the closing stages of Saints defeat to Castleford on Thursday night with what appeared to be an Achilles injury.
And with winger Tommy Makinson, who has filled in at the position several times, out with a broken leg, that leaves Cunningham short of options.
There has been no official confirmation on the extent of McDonnell’s injury but Cunningham appeared resigned after Thursday’s defeat to Castleford to losing his new signing for some time.
“It’s just the way our luck is going at the minute,” Cunningham added. “It’s a shame for Shannon because he’s filled a great gap for us and he was very good again tonight. It’s unfortunate for the kid.”
Lomax injured his cruciate ligament at the start of the season while ex-skipper Wellens is struggling with a hip injury which Cunnginham revealed last week could force the club legend to retire.