The permutations are complex, but depending on the outcome of Monday's earlier match between Argentina and Austria in Texas, defeat for either Algeria or Jordan could mean their World Cup exit after only two games.
Jordan were expected to showcase their resolute defending on their World Cup debut but rattled Austria with ruthless and relentless counter-attacking in a dramatic end-to-end game that finished a flattering 3-1 in favour of the Europeans.
Al-Nashama, or the "noble ones", have little choice but to go all out against Algeria at the home of the San Francisco 49ers, where a draw on Monday might require heroics in their last group game against defending champions Argentina, and a loss could see their early elimination.
Ali Olwan, scorer of Jordan's first-ever World Cup goal, said his side would build on their attacking performance, learn from defensive lapses and deliver more against Algeria.
"The smart one learns from his mistakes and doesn't repeat them," he said. "I promise you that in the next match, God willing, we will give our best and be better."
Algeria are in a similar boat after their 3-0 defeat by Argentina in what turned out to be the Lionel Messi show, after he scored a hat-trick to tie for all-time leading World Cup goalscorer. Algeria were unhappy with the refereeing and lodged a complaint with FIFA.
Argentina can win the group with a victory on Monday, provided Jordan do not beat Algeria. Austria could also win the group if they beat Argentina and Jordan do not lose.
Known as the Desert Foxes, Algeria last appeared at the 2014 World Cup and are hoping the expanded tournament could help their talented squad reach the knockout rounds for the second time and go beyond their defining 1982 upset of West Germany.
With Argentina out of the way, Algeria will be eager to energise their campaign, knowing they could exit the World Cup on Monday if they lose to Jordan and Austria can get at least a point against the world champions.
"We need to make sure the team have that belief because we know that we can do it," said Algeria's coach Vladimir Petkovic.
"Our other two opponents in this group still need to face Argentina, so we still have our fate in our own hands."