The Vikings entered the eight-team mini-league as the lowest-ranked side from the top flight after losing their last four games of the regular season.
Last week’s home defeat by Warrington Wolves in their Qualifiers opener brought the threat of relegation into sharper focus and left Widnes with little room for error.
“The must-win games are against Championship sides,” said coach Betts. “Whether it’s the second or third game, you’ve got to beat the Championship sides. We can’t hide from that fact.
“We know they’re going to be competitive and are striving for something more while we’re trying to protect something. That creates a different kind of focus.
“Ultimately, every single game against a Championship side is a must-win.”
Sunday’s opponents Halifax were eight minutes away from opening the Qualifiers with a stunning win at Hull KR while London Broncos gave Catalans Dragons a major scare in the south of France.
Betts is under no illusions about how difficult it will be to achieve his target of four wins out of four.
He added: “London are a full-time outfit, Featherstone have got plenty of Super League experience in their group, Halifax have had a taste of it a couple of times and we know Hull KR are basically a Super League side playing in the Championship.
“It’s a tough competition. You’ve got four form teams playing against sides that have struggled with that momentum throughout the year.
“Ultimately, it’s not about how good the rugby is, it’s about gritting your teeth and surviving.”
Halifax secured their place in the Qualifiers the hard way by beating Toulouse, Featherstone and Hull KR in successive weeks. Betts has warned his side the trip to The Shay throws up different challenges.
“Richard Marshall has got them playing good rugby,” said Betts.
“I’ve seen their game against Hull KR and they’ve got some good quality players in their team. They play with good shape and understand what’s required.
“It’s always tough going to their place. It’s a different sized pitch, a different environment and a tough place to go and get a result at the best of times.
“But we’re taking a bit of confidence out of the Warrington performances and we seem pretty healthy at the moment.”
Featherstone travel to London in Sunday’s other game aiming to bounce back from their 38-12 home defeat by Leigh.