Saints fear full-back Jonny Lomax could be facing another lengthy lay-off after injuring the same knee which caused him to miss much of last season.
The luckless 23-year-old (pictured) hurt his left knee after going up for a high ball against Wakefield earlier this month and is set to visit a specialist in Yorkshire this week for a second opinion.
He missed several months of the 2014 season after snapping his cruciate ligaments against Catalans Dragons last summer.
Keiron Cunningham said: “We want to do the best by the kid as he’s not had much luck with injuries.
“It’s the same knee as last year, which is always a worry, and we should know more later this week.
“It’s a shame - he’s a super player.”
Mark Percival, who also suffered a knee injury in the same game, is set to be out for about six weeks.
He is currently in a knee brace after damaging his medial ligaments.
Saints coach Cunningham told how player welfare is always at the forefront of his mind, and cited the recent examples of Mark Flanagan and James Roby.
He said: “Flash (Flanagan) has had surgery on his eye after damaging his tear duct. He’s desperate to play but there’s life after rugby league and it would be selfish of me as his coach to push him before he’s ready - especially when it’s something that could affect his livelihood in 10 or 15 years time.
“That one will be up to the specialists.
“We need to look after Robes too. He’s one of the club’s biggest assets and, if I was to push him too hard and break him, he would be a big loss. Lance Hohaia did really well against Widnes anyway.”