Darlington Nagbe (left) celebrates with Christian Pulisic after scoring the winner against Ecuador. Getty Images

In one of the U.S. men's national team's final tune-ups ahead of next month's Copa America Centenario, Jurgen Klinsmann's squad pieced together a vintage underwhelming performance. By now, the formula is familiar: a lackluster attack, solid yet sloppy defending, and a couple moments of magic to keep some semblance of hope alive.

One moment ended up being enough for the USMNT against Ecuador on Wednesday night. In front of a sparse crowd in Frisco, Texas, the U.S. fought Ecuador to a scoreless draw for 89 minutes. Then, in the 90th minute, an unexpected hero emerged.

Thanks to a clever run by DeAndre Yedlin and a well-placed header by Bobby Wood, Darlington Nagbe wound up with a chance to put away a game-winning goal in the final minutes of the match. Nagbe buried the chance, which marked his first career goal for the U.S.

Despite that unexpected moment, the game felt more like a practice game than an international friendly. The intensity level started low and only peaked in the final minutes of the match.

The U.S. began carelessly, as a turnover by U.S. centerback John Brooks gave Ecuador an early look at goal. Minutes later, U.S. goalkeeper Brad Guzan was forced to save at the near post due to an error from Brooks' partner, Steve Birnbaum. Who Klinsmann should pair together at centerback has always been a question lacking an obvious answer, and the opening few minutes certainly didn't offer a solution.

The defense eventually settled down, but the attack never took off in the first half. Playing in a 4-3-3, the U.S. lacked creativity. When the speedy Yedlin finally broke loose down the field, he botched his run with a pass to no one. When Clint Dempsey played a perfect ball to set up Gyasi Zardes alone in the box, the breakaway was ruined by a heavy first touch. In the 36th minute, Jermaine Jones had a chance to play in Fabian Johnson on the left side of the box. They failed to connect.

Perhaps the worst aspect of the first half? The team's reluctance to involve Dempsey.

Put it this way, it's not the best sign when Guzan is the most noticeable American player on the field. Guzan wasn't asked to make any spectacular saves, but he handled all of Ecuador's chances with relative ease.

The second half offered more promise. Minutes after the break, a perfectly placed cross off a corner by Michael Bradley should've resulted in a goal at the far post, but neither Birnbaum nor Dempsey could finish. In the 60th minute, the U.S. mounted its best attack of the game when halftime substitute Bobby Wood found Dempsey inside the box. Dempsey's shot near the penalty spot careened off a defender, though, and Bradley's follow up from outside the box skied well over the crossbar.

The chances began to mount. In the 72nd minute, after a bout of possession, Graham Zusi weaved his way into the box and slotted a cross toward the far post. Alejandro Bedoya met the cross, but his shot slid past the opposite post and out of play. In the 75th minute, a poor clearance fell to Wood in the middle of the box. Wood failed to corral the ball and Ecuador escaped.

Just when it looked like neither team would break through, Yedlin beat his man on the right edge of the box and played in a cross. After a botched clearance, the ball hung in the air. Wood won the 50-50 with his head and redirected the ball to Nagbe, who provided a spark in an otherwise uninspiring USMNT performance.

To be clear, the outcome of the game hardly matters; the way in which the U.S. played to earn the win is what's important. And based on the 90 minutes the USMNT presented to us on Wednesday, don't be surprised if the team struggles to survive at the Copa America Centenario. Hopefully, for the simple sake of watchability, the U.S. won't sleepwalk its way through games that will actually matter in the weeks to come.