Saints are hoping that second row forward Dominique Peyroux will be given the green light to return to full training early next week.
The 29-year-old former Gold Coast Titans and New Zealand Warriors star broke his arm in a Super League clash against Warrington Wolves at the Totally Wicked Stadium in late July and been sidelined since then.
He underwent a further scan last week which showed a big improvement and is due to see a specialist again next Monday when he is expected to be given the all-clear.
Head coach Justin Holbrook said: “The latest scan went really well and we are hoping he will be available before the semi-finals and able to get a couple of matches under his belt.
“Dom is an important part of our squad and we’ve missed him during his enforced absence.”
Saints will announce their squad for Friday night’s home game against Hull FC at lunch-time today (Wednesday) but it is unlikely to include skipper James Roby who is still suffering from a slight shoulder injury he picked up in the Wigan derby a couple of weeks ago.