Both these teams lost their first games of the 2017 CONCACAF Gold Cup, which makes this match pretty much a must-win.
Of the two, El Salvador would perhaps be less disappointed with a draw. It would require the Salvadorans to beat Jamaica in their final game of the group stage to have a shot at making it to the quarterfinals, but they have no reason to fear that challenge.
Curacao, on the other hand, has to play Mexico in its final game of Group C. El Tri is something close to a prohibitive favorite to win that game. Curacao needs to beat El Salvador to entertain any significant hope of featuring in the knockout rounds.
Per livesoccertv.com, here's where to find the game if watching from the USA: