This will be the first time since the 2010 campaign that La Selecta have made it to the final stage of qualifying, while the Yanks are hoping to return to the finals after missing the World Cup in 2018 for the first time since 1986.
Match preview
It has been over 29 years since El Salvador last punched their ticket to the World Cup, when they got some help from Honduras, who drew Mexico 0-0 on the final day of qualifying in 1981, enabling La Selecta to travel to Spain for the 82 finals.
Since that time, there have been many dark days in Salvadorian football, as this team have only made it to the final phase of qualifying twice since their 98 campaign.
However, Hugo Perez has been instrumental since returning to his homeland, guiding El Salvador to a first-place finish in the opening round of qualifying for these finals before cruising past Saint Kitts and Nevis 6-0 on aggregate to advance to this stage.
As a member of the National Soccer Hall of Fame, Perez was an integral part of the Americans' rise to prominence in CONCACAF in the mid-90s, representing the Yanks when they hosted the World Cup in 1994, and he has played an equally important role in moulding La Selecta into a prominent group who have risen to number 64 in the world according to the latest FIFA rankings.
At the Gold Cup earlier this year, they showed that they belong with the heavy hitters in this region, advancing to the quarter-finals while giving Mexico and Qatar all they could handle in their two defeats.
Now is when they will hope that all of their hard work and the growing pains they have gone through pays off.
This may be the most impressive crop of talent the Salvadorians have assembled this century in all facets of the game, scoring 19 goals in the first two qualification rounds while conceding only once, although it is fair to say that none of those opponents were of the same calibre as the Americans.
It was considered a national humiliation when the United States failed to qualify for the World Cup in 2018, losing their final match, 2-1 to Trinidad and Tobago.
Following that failure Gregg Berhalter was brought in to restore some pride in this team, who, next to Mexico, have been one of the most dominant sides in CONCACAF for years.
The team has gone through plenty of changes in the front office and on the field, and the new crop of young Americans will be out to prove that what happened in the 2018 campaign will not happen again.
It has been quite the year for Stars and Stripes, winning the CONCACAF Nations League and the Gold Cup, with 12 wins and only one defeat so far in 2021.
In their recent triumph at the Gold Cup, we got a glimpse of how deep this team is, as they were able to win the tournament with a relatively inexperienced side, many of whom were making their international debuts.
Most of their regulars will be in the fold for this match but seeing what the newcomers achieved last month has to give Berhalter and his team a lot of confidence going into this qualifying round.
Four years ago, they were slow out of the gate, losing their opening two matches to Mexico and Costa Rica, which led to the dismissal of Jurgen Klinsmann in favour of Bruce Arena, who did not fare much better, winning only one of his last five matches of qualifying in at the helm.
El Salvador World Cup Qualifying - North Central America form:
El Salvador form (all competitions):
USA form (all competitions):
Team News
Perez will have to look to other sources to score as striker David Rugamas, who leads all players in qualifying with eight goals, will not be available.
Joaquin Rivas scored three goals at the Gold Cup, while goalkeeper Kevin Carabantes made just his third appearance for his country in their 0-0 draw in a friendly against Costa Rica before being replaced at half-time by first-choice keeper Mario Gonzalez.
Alex Roldan will hope to get the better of his brother Cristian in this game, with the siblings playing as teammates in MLS for the Seattle Sounders, though Cristian Roldan chose to play for his country of birth, the United States.
After missing out on their Gold Cup triumph earlier this year, midfielder Christian Pulisic is back and looking to add to his World Cup qualifying tally, scoring seven goals in their last campaign, putting him in a tie with Michael Bradley for seventh all-time.
Miles Robinson was the hero for the Yanks at the Gold Cup, scoring the game-winner in the final against Mexico in extra time, his second of the tournament, while goalkeeper Matt Turner collected five clean sheets but might not get to start on Thursday with Manchester City reserve keeper Zack Steffen back with the team.
The US have 10 players on their roster for this game who will also be taking part in the Champions League this year, including Brenden Aaronson, Tyler Adams, John Brooks, Sergino Dest, Weston McKennie, Jordan Siebatcheu, Giovanni Reyna, Tim Weah, along with Steffen and Pulisic.
El Salvador possible starting lineup:
Gonzalez; Larin, Gomez, Zavaleta, Tamacas; Moreno, A. Roldan, Ceren; Henriquez, Rivas, Perez
USA possible starting lineup:
Steffen; Dest, Zimmerman, Robinson, Sands; Adams, Acosta, C. Roldan; Reyna, Sargent, Pulisic
We say: El Salvador 0-2 USA
La Selecta have never beaten the United States in a competitive match, managing only four draws against them all-time, and with the Americans at full strength and winning two CONCACAF trophies this year, it is hard to imagine a scenario in which El Salvador can pull of an upset.