Ashurst suffered damage to a lower leg in Trinity’s win at Hull KR last Thursday.
Caretaker-coach Willie Poching revealed: “We don’t know the full extent, but we know it’s pretty bad and it’s looking likely he will miss the rest of the season.
“He has got more scans and has to see a specialist, but he is a big loss for us.”
What is happening to former Leeds United star Raphinha at Barcelona amid latest farce and deadline
Leeds United ‘express interest’ in transfer as ‘decision made’ over player’s future
Leeds United and Crystal Palace ‘monitoring’ £30m striker, Whites could be ‘offered’ Aston Villa star
Leeds United fans are completely divided on what Mateusz Klich did in training
Southampton v Leeds United team news: Big first for new signing but star misses out
The good news for Trinity is centre Reece Lyne’s return from injury for tomorrow's (Monday's) derby at home to Leeds Rhinos.
Hooker Harry Bowes has been recalled to the initial squad, while three-quarter Joe Arundel and forwards Tinirau Arona and Brad Walker retain their place after not being selected three days ago.
Leeds coach Richard Agar will select from the 21 players named ahead of last Wednesday's victory at Wigan Warriors.
Stand-off Callum McLelland could return after illness and outside-back Jack Broadbent - who has not played since suffering an ankle injury in early July - is also in contention, along with forwards Sam Walters and Jarrod O’Connor.
Pack star Zane Tetevano has received a three-game penalty notice after the RFL’s match review panel charged him with a grade C reckless high tackle on Wigan’s John Bateman, but - because of the bank holiday weekend - the ban does not come into effect until after today’s fixture.
It will be Joe Westerman’s 300th Super League appearance and Trinity teammate Liam Kay is on 199 career games.
Leeds’ Richie Myler needs one appearance to reach 350 for his career and Ash Handley’s next game will be his 150th.
Wakefield Trinity: from Johnstone, Lyne, Kay, Miller, Lino, Fifita, K Wood, Arona, Tanginoa, Westerman, Pitts, Battye, Batchelor, Senior, Crowther, Arundel, B Walker, Aydin, Kershaw, Hampshire, Bowes.
Leeds Rhinos: from T Briscoe, Newman, Handley, Lui, Leeming, Prior, Martin, Tetevano, Dwyer, Myler, C Smith, Holroyd, Vuniyayawa, Thompson, Walters, McLelland, L Briscoe, Donaldson, O’Connor, Broadbent, Gannon.
Referee: Chris Kendall (Huddersfield).
Kick-off: Monday, 3pm.
Support the YEP and become a subscriber today. Enjoy unlimited access to local news and the latest on Leeds United, With a digital subscription, you see fewer ads, enjoy faster load times, and get access to exclusive newsletters and content. Click here to subscribe.