Terry O'Connor says that should Wakefield beat St Helens on Thursday, live on Sky Sports Arena, it will spell the end of the Saints' season and basically ensure a top-four place for Trinity.
Saints slipped to sixth in the Super 8s after last week's 16-26 defeat at home to Wigan, their third defeat in a row, and O'Connor has said if they lose at Belle Vue their season is over.
"If they get beat in this game, their season will end," O'Connor told Sky Sports News on Wednesday. "There is a lot of expectation on Saints every time they take the field, the fans expect and demand so much from them.
"But they were up against a very determined Wigan side who were beaten the week before in the Challenge Cup final, and that was the best game Wigan could have played: against Saints in a derby.
"Saints still have the expectation on them but Ben Barba is one game into his Saints career and hopefully they'll be feeling the pressure is off them a bit more and they'll be heading to Wakefield looking to do a job, but it's going to be very difficult."
In contrast to St Helens, Wakefield sit fourth in the table and have their destiny in their own hands heading into Thursday's clash.
Wigan's victory means their advantage remains a slender one at just one point, but O'Connor was full of praise for Chris Chester's men and has tipped them for a semi-final place should the result on Thursday go their way.
"They've (Wakefield) been excellent all year," O'Connor added. "You look at the job Chris Chester's done, he's built a very good side that really do back themselves.
"They're not star-studded like some of the other teams in Super League, they don't spend as much money but what they do is get through the sets well and they've got players who turn up and perform.
"They've just signed a lad from Australia and the Newcastle Knights in Tyler Randell, who made his debut against Salford, and he certainly made a big impact. They've got a big effective bench and they are a team that can trouble a lot of sides.
"You look at the way they play the game: they've got some good half-backs and Chester will certainly give them free reign to go and play and they'll be up against a side they'll think they can beat.
"If they nail this game and get the two points, I think they'll finish in the top four, which is amazing when you consider at the start of the year they were many people's favourites to finish down the bottom end of the table."
On Friday, Hull FC host Wigan on Sky Sports Arena in a repeat of the 2017 Challenge Cup final two weeks ago and O'Connor expects an intriguing clash between the sides.
"Hull got to this point last year and the wheels fell off," he said. "They won the Challenge Cup and all of a sudden they just couldn't continue with the great form that had got them near to the top of the table.
"They'll have hopefully learned from those mistakes and Hull are another talented side when you look at Marc Sneyd and Mahe Fonua, who both played really well in the cup final. I'm not so sure they are going to have that much space this week.
"In playoff football, like Hull FC, Wigan have shown they can play in those big games and get to finals. They are a very good side and I always expected them to react as they did last week. You write them off at your peril.
"Wigan are a very good side, Sam Tomkins looked back to his back last week, Sean O'Loughlin is a player who takes control and they have players who can get under your skin but play as well.
"This will be an absolute belting game, a repeat of the Challenge Cup final. It went in Hull FC's favour a couple of weeks ago but Wigan are going to be so determined to get the job done up in Hull."