Speaking with Football Presse, Keller also was eager to highlight the huge importance of captain Christian Pulisic and praised coach Mauricio Pochettino for delivering when it mattered most.
The former United States goalkeeper remains one of the most respected voices in American soccer. Keller earned 102 caps for his country, represented the USA at four World Cups and enjoyed a distinguished club career in England and Germany before moving into broadcasting and punditry.
Speaking to Football Presse on behalf of World Cup 2026 winner odds after the USA's emphatic 4-1 victory over Paraguay, Keller admitted the performance exceeded his expectations following what he described as an inconsistent period under Pochettino.
The Americans produced one of the most impressive displays of the tournament so far in Los Angeles. An early Damian Bobadilla own goal set the tone before Folarin Balogun struck twice in the first half. Paraguay pulled one back after the break, but Giovanni Reyna's late strike completed a dominant victory for the co-hosts. ([FIFA][1])
While many supporters have become excited about the team's prospects, Keller warned against getting carried away after just one game.
"Oh, definitely, no question about it," Keller told Football Presse when asked if the result surpassed his expectations.
"There's been so much inconsistency with the team under Pochettino, we just never really knew what to expect.
"We were on a four-year pre-season without qualifying games. We never really had that true test to see where everybody was at.
"Whatever Pochettino was doing and thinking worked in that first match. Now it's basically a case of maybe bringing expectations down because what that first match did was just kind of blow it through the roof."
What particularly impressed Keller was not simply the scoreline, but the aggressive mentality displayed by the United States throughout the contest.
The former goalkeeper pointed to the team's willingness to continue attacking after taking an early lead, rather than retreating into a defensive shape.
"I love seeing that there wasn't this, 'We've scored, now let's back off'," he explained.
"The plan was to attack and they attacked and they did it tremendously."
Keller also highlighted the way the Americans responded after conceding in the second half.
"We had seen from the US over the last couple of years, particularly against good opposition, that they'd play really well and then when they made a mistake they'd struggle.
"They made the mistake at 3-1 and you think, 'Okay, now let's see what happens.' Then they kind of re-established dominance and got that tremendous goal at the end of the game."
A major talking point following the victory has been the influence of Pulisic, who played a key role before being withdrawn after suffering a knock. The AC Milan star is currently being monitored ahead of the next group-stage fixture. ([SB Nation][2])
For Keller, there is no doubt that Pulisic occupies a similar position within the American setup to the role Lionel Messi has played for Argentina.
"No, he's not the be-all and end-all, but like any team, your star's your star," Keller said.
"If your star plays well, it's amazing how the team plays well.
"Argentina can get a result without Messi and Portugal can get a result without Ronaldo. But Argentina's almost unstoppable when Messi's unstoppable.
"When your star is absolutely in that kind of form, it just brings everybody else along."
Keller believes Pulisic's unique qualities elevate the entire side and create opportunities for those around him.
"They know that Christian is capable of doing something that pretty much nobody else on the pitch can do.
"The form that he was in in that first half was ridiculous. I think it just drove everybody else."
He added that the wider team also deserves recognition for supporting their captain's influence.
"Christian was tremendous, but the rest of the team was also very good."
Keller reserved special praise for Pochettino, acknowledging that the Argentine coach had faced growing scrutiny before the World Cup began.
"There was a lot of question marks," Keller admitted.
"There were a lot of occasions where I didn't like what I saw.
"But I also prefaced that by saying this is a four-year pre-season. We don't have qualifying games. There's nothing of urgency.
"Nothing really matters until that first match of the World Cup."
The verdict after the Paraguay victory was clear.
"Boy, did it matter. And boy, did the team and Pochettino get it right."
With Australia and Türkiye still to come in Group D, Keller believes tougher challenges lie ahead. Yet after the manner of the opening-night performance, there is finally a sense that Pochettino's vision for the United States may be coming together at exactly the right time.