Wakefield are sending winger Tom Johnstone to a neurosurgeon after he suffered a setback in his recovery from concussion.
Johnstone, who has been earmarked for a place in England’s World Cup team, has not played since picking up a head knock in Trinity’s Challenge Cup defeat by Catalans Dragons in early April.
He had targeted Friday’s match at Leeds for his comeback but is now facing another lengthy spell on the sidelines.
Wakefield coach Chris Chester said: “Tom only got to see a specialist on Monday and it doesn’t look great to be honest.
“He’s going to see a neurosurgeon. He’s still getting headaches after all this time. We put him on a bike a few days ago and straight away he got some headaches.
“I think it will be a minimum of another four weeks now. There are strict guidelines and we’re led by our medical people.”
The 25-year-old spoke of his “dark times” as he overcame two major knee injuries earlier in his promising career and Chester says the player is in the hands of the club’s player welfare officer Stuart Dickens.
Chester said: “We’ve just got to try and get him through this tough period he’s going through. Obviously Stuart is working closely with him.
“It’s really tough on Tom and it’s tough on everybody at the club because we know how important a player he is to this team.
“Fingers crossed we get some good news on Monday. The kid is obviously really down and disappointed but I’m pretty sure he’ll come through the other side.”
Wakefield skipper Jacob Miller is still a week away from recovering from a knee injury, while centre Bill Tupou will miss Friday’s game with a calf injury and his likely replacement, Jack Croft, suffered a season-ending anterior cruciate ligament (ACL) rupture while playing on loan at League 1 club Oldham.
Chester added: “It’s gut-wrenching for him and just Jack’s luck. With Bill Tupou being out he was going to play for us this week.
“You are probably talking nine to 10 months so it’s probably next season and it’s tough going for him but he’s got a lot of support around him.”