Paraguay manager Gustavo Alfaro said Bolivia would have an "extra player" on the pitch when the teams meet in a crucial World Cup qualifier on Tuesday.
The match in El Alto, a municipality on the outskirts of Bolivian capital La Paz situated more than 4,000m above sea level, will pose a challenge unlike any other his team has faced, Aflaro said.
"It's going to be very complicated," the Argentine told a news conference on Sunday. "We have to pretend that we are going to play a game that is 120 minutes long, not 90 minutes, because of the extra effort that will be required.
"It's as if Bolivia has one more man, with that extra man being the altitude. That's how we're thinking about the match. It's obviously an advantage for Bolivia because they are a team that plays differently at that altitude."
Paraguay, vying for its first World Cup berth since 2020, is currently sixth in the 10-team South American zone qualifiers with 16 points from 11 games, six points behind leaders Argentina.
Bolivia, who has not qualified for football's showpiece tournament since 1994, is eighth, four points further back.