ARLINGTON, Texas -- United States men's national team head coach Gregg Berhalter said all 26 players are available for Sunday's Copa América opener against Bolívia amid concerns over the fitness levels of midfielder Tyler Adams and forward Josh Sargent.

"From my understanding, everyone will be available [Sunday] to play some role," Berhalter told reporters at AT&T Stadium on Saturday. "I can't go into specifics about length of time for Josh, but I know he's available to play a role."

Sargent last played for his club, Norwich City, on May 16, when he suffered a foot injury. He did not feature in either of the USMNT's June friendlies ahead of Copa América but was named to the final roster for the tournament.

Adams played the final 14 minutes of the USMNT's 1-1 draw with Brazil on June 12. Adams played limited minutes for Bournemouth last season because of a hamstring injury and back spasms.

"Tyler's been sharp," U.S. defender Chris Richards told reporters on Saturday. "You wouldn't have known that he hadn't played many games this season. I think that's one of the reasons that he's considered one of our captains, because [of] the aura that he has, whether it's him leading from the sidelines or him leading on the pitch."

The surface at AT&T Stadium should not be a factor in whether Adams or Sargent plays on Sunday. Both Berhalter and Richards praised the surface, a welcome sight after Argentina players criticized the pitch at Mercedes-Benz Stadium in Atlanta at the tournament opener on Thursday. Both stadiums feature sod laid over artificial turf.

"We were here in Nations League in March and this field appears to be much better," Berhalter said. "There seems to be a base of sand [which] makes it much softer, but the grass itself looked really good and we were pleasantly surprised with the playing surface."

Berhalter expects an "aggressive" Bolivia team in Sunday's Copa América opener. The USMNT coach noted that teams like Bolivia, the lowest-ranked team in South America, take pride in big tournaments such as Copa América since World Cup appearances are rare.

Panama and Uruguay also await the hosts in the group stage.

"We'll be presented with different challenges in this tournament, sometimes a different brand of soccer, and for us it's about how we adapt to that," Berhalter said. "I think when you look at the top teams in the world, that's what they are the best at doing, is adapting.

"You look at a team like France, they can play on the offense, they can play on defense; whatever they need to do to be successful is what they do. And I think that's still something that we're developing.

"One thing I know for sure [is] that our most success is going to come from being able to limit our opponents' high-scoring goal-scoring opportunities. If we can do that in each game, we'll have a chance, because we always create enough chances to score a goal."