If Argentina want to repeat as Copa America champions, they'll need to get by Canada, a side that frustrated them in the debut match of the tournament.
On that occasion, Argentina beat Canada 2-0. The final score, however, didn't tell the story of the match with Canada creating some opportunities to score and generally making life difficult for the Albiceleste.
At the same time, Argentina felt they could have won by more as they themselves failed to take advantage of their own opportunities.
The elephant in the room is the fitness of Lionel Messi.
Messi has been dealing with a leg injury since the group stage win over Chile. Unsurprisingly, his availability was the big questions heading into Lionel Scaloni's press conference. Scaloni was straight to the point and confirmed Messi will play against Canada.
"It's an easy decision for me," Scaloni said. "It's a fairly honest decision: I ask him how he feels. If he says 'I'm not good,' then he will play the last 30 minutes. When he's available, he will play."
Canada manager Jesse Marsch is keenly aware they'll need to game plan for Messi regardless of his fitness or whether he starts or plays the final 30 minutes.
"We didn't do well enough with Messi in the last match, he was able to run free at our goalkeeper too much," Marsch said. " We won't man mark, but we will certainly place an emphasis on how to defend him. How to keep track of him will be really important, and the things that make it difficult for him like limiting his space is out number one thing."
At 37-years-old, Messi isn't as physically quick as he used to be. However, his vision on the pitch remains second to none. Limiting his space will be important as he's still able to pick out a teammate and deliver that inch-perfect pass.
Argentina have other players that can cause problems like Angel Di Maria and Lautaro Martinez. The midfield, anchored by Alexis Mac Allister has also been one of their strengths.
The fact that these sides met at the beginning of the tournament could be an advantage. That it's a knockout match could alter things with both sides being somewhat cautious to start.
Canada is CONCACAF's lone representative following the elimination of Mexico and the USA in the group stage and Panama's loss to Colombia in the quarterfinals.
Argentina are the defending champions and will want to add more silverware to their trophy cabinet. Should they get past Canada, they'll face the winners of Uruguay and Colombia in the final on July 14.