Another defeat for either would all-but end their attempts to make it into the knockout stages.
For Senegal in particular, that would be a crushing disappointment. Champions of Africa at last, going home so early would be a catastrophe despite the absence of talisman Sadio Mane through injury.
Qatar, meanwhile, have been building towards this tournament for 12 years and surely have more to offer than they did against Ecuador in the opening game. If they don’t, what was the point?
Here’s how to follow all the action today.
Where to watch Qatar vs Senegal
TV channel: In the UK, the match will be televised free-to-air and live on BBC One, with coverage beginning at 12.45pm GMT ahead of a 1pm kick-off.
Live stream: The BBC iPlayer will broadcast the match live online.
Live blog: You can follow all the action via Standard Sport’s live blog, with expert analysis from Nizaar Kinsella in Al Thumama.