Christian Pulisic was substituted at halftime of the United States' 4-1 World Cup opening win over Paraguay on Friday after taking a kick to his left calf, with manager Mauricio Pochettino describing the move as precautionary.

"He got a kick in the calf and at the end of the first half he started to feel tight and we didn't want to take any risks," said Pochettino. "It was difficult for him to walk. But [we] hope that it's not a big issue and he can be ready for the next one."

Pulisic was direct after the match, expressing optimism about his condition.

"I just got a bit of a kick first half, so I'm really hoping that it's nothing," said Pulisic. "Taking a little bit of precaution today, but I'm hoping I'll be fine the next few days.

"Just the back of my leg, my calf area. But I've had similar things before and I'm staying positive. I don't think it's anything at all."

Pulisic had been the standout performer in the opening half, helping force a Paraguay own goal and setting up Folarin Balogun's first of two strikes before Sebastian Berhalter replaced him at the break. The United States led 3-0 at halftime, the first time in program history the team has held a three-goal advantage at the interval in a World Cup match.

Balogun's two-goal effort marked the first time a United States player scored multiple World Cup goals in a single game since Bert Patenaude's hat trick in 1930.

The United States next face Australia in Seattle on June 19 before closing Group D play at SoFi Stadium against Turkiye on June 25. The United States are currently 64 percent favorites to beat Australia outright, according to the latest World Cup odds.