MEXICO CITY— Five starters are injured heading into a match in the thin air of Estadio Azteca, a World Cup berth remains uncertain and an even more important game may loom for Christian Pulisic and his U.S. teammates.

The U.S. could clinch a return to soccer’s showcase with two games to spare if it wins Thursday night against Mexico, Panama loses at home to last-place Honduras and Costa Rica fails to win at home against first-place Canada.

In October 2017, Pulisic fell to the field and buried his head in a hand when the Americans lost at Trinidad on the final night and were eliminated.

“I’ve been looking forward to it for years now. Obviously, without accomplishing it last time around, it’s been a massive goal of mine and this team’s,” Pulisic said Wednesday. “I’m obviously excited.”

Canada leads North and Central America and the Caribbean with 25 points, and the U.S. is second with 21, ahead of Mexico on goal difference. Panama is fourth with 17 points, followed by Costa Rica with 16 and El Salvador with nine. Jamaica and Honduras have been eliminated.

The top three nations qualify for the 32-nation field in Qatar this November, and fourth place advances to a June playoff against the Oceania champion, likely New Zealand.

“We’re in good shape to qualify. There’s no need to change dramatically what we have been doing,” left back Antonee Robinson said. “We just need to keep going, keep confident in ourselves.”

Next up is Sunday’s match against Panama in Orlando, Florida, when the U.S. could clinch with a victory as long as Costa Rica doesn’t win its final three matches.

Some in a nervous fan base suggested U.S. Coach Gregg Berhalter rest top-line players to keep them fresh for the home game and the March 30 match at Costa Rica, where the U.S. has never won.

“I heard that argument, we should plan a B team. And what I did is I took it to the staff and we debated it. We looked at all sides of it,” Berhalter said. “We came out with our answer and you’ll see tomorrow.”

The U.S. is coming off three straight wins against Mexico, in the CONCACAF Nations League final at Denver in June, at the CONCACAF Gold Cup final at Las Vegas in August and in a qualifier at Cincinnati in November.

“You almost see growth in each of those games, culminating in the last one, in the qualifier, where the guys were really, really confident going into the game,” Berhalter said. “We can’t let our guard down. Our record here is horrendous. The odds are against us getting something out of this game. We know that. We realize that. And that’s just how it is.”

Azteca is a notoriously difficult place for visitors, with steep stands and a clamorous crowd that had drawn discipline from FIFA for homophobic chants – the Mexican Football Federation is limiting attendance in the 87,000-capacity venue to about 50,000 as part of crowd-control measures.

More accustomed to the thin air at altitude 7,200 feet than opponents, El Tri has 40 wins, nine draws and two losses in qualifiers at Azteca, the defeats to Costa Rica in 2001 and Honduras in 2013. The U.S. is winless with five losses and three draws at Azteca in qualifying, and winless in 10 competitive matches with seven defeats.

“Of course, we’re aware of the altitude. Some guys may be more used to it than others,” Pulisic said.

Nearly half the U.S. starters from the Jan. 30 qualifier at Canada are injured: goalkeeper Matt Turner (foot/ankle), defenders Sergino Dest (strained left thigh) and Chris Richards (right ankle), and midfielders Brenden Aaronson (knee) and Weston McKennie (two broken bones in left foot).

Midfielder Gio Reyna is back for the first time since straining a hamstring in the opening qualifier on Sept. 2. Tyler Adams, another key midfielder, has not played a full match since returning from a hamstring injury in the Jan. 30 qualifier at Canada.

Berhalter wouldn’t divulge if Zack Steffen or Ethan Horvath will start in goal or even whether Sean Johnson was in contention.

This may be the last U.S.-Mexico qualifier of great import – or possibly at all. Both receive automatic berths to the 2026 tournament, which they co-host with Canada, and with the expansion of the World Cup from 32 nations to 48 after this year’s tournament, CONCACAF likely will have six berths and develop a format that keeps the region’s powers from competing in the same group.

But first comes a three-game stretch that will define this rebuilt American team.

“One thing I told the staff in our meeting as we started camp was, this is probably the biggest week of our lives as professional coaches,” Berhalter said.