The 32-year-old Farrell is set to be sidelined for two months after damaging his knee in the 30-10 win over St Helens nine days ago.
“It’s quite a big one,” Warriors coach Matt Peet said at the play-off launch at Salford.
“The specialists are saying eight weeks but there are things we can do to fast track that. We’ll be doing everything we can to try and get him back on the field but we are up against it.”
With the Grand Final just under three weeks away, Peet is resigned to being without Farrell for his club’s semi-final on Friday, September 16, and admits he is unlikely to be fit for the start of the World Cup a month later.
“It will depend on what England want to do, whether they’re willing to carry someone who might not be right for the first game,” Peet said.
“That’s Shaun’s decision to make, he could play a part in the World Cup.”
England coach Shaun Wane has already spoken to Farrell about his plans, with the 24-man squad due to be announced by September 24.
The loss of Farrell is a body blow to Wigan’s prospects of completing the League and Cup double.
“He’s in the Dream Team so obviously he’s one of the most consistent players in the competition,” Peet said.
“To lose someone like that is a blow but that’s what squads are designed for.
“Every team has gone through it. We think we are really well equipped to continue some decent form but it is a blow.”