The "superclasico" is regarded by fans as the biggest event of the season and victory can make up for not lifting the title or playing badly in the rest of the matches put together, while defeat can only be cured in their next clash.
The match at River's Monumental stadium is a 53,000-capacity sellout.
The club, which has topped gate takings in the last three tournaments, sold 35,000 seats in eight hours on Tuesday before putting the "populares," tickets for the old-style standing terraces behind the goals, on sale from Wednesday.
Alfio Basile's team, in mid-table with 14 points, are five points behind leaders San Lorenzo at the halfway stage.
"Riquelme is among the three best (players) in the world. Riquelme conducts everything," former Argentina coach Basile, who nearly quit when Boca had gone six matchers with only one victory, told Radio del Plata.
Basile's team, despite playing away, are the favourites after turning the corner with a 3-2 home victory over title holders Velez Sarsfield three weeks ago.
However, River are relying heavily on 35-year-old former Argentina midfielder Matias Almeyda, who filled in at centre back in last weekend's 0-0 draw at Huracan, to steady a young team, and on fellow 1998 and 2002 World Cup veterans Ariel Ortega and Marcelo Gallardo to create chances.
"You have to play Boca with your heart more than with your head," said Astrada, a one-club veteran who shared many Boca clashes with the trio.
"It's a match apart. It doesn't matter in what position (in the standings) either side is coming into it, what matters is to beat our eternal rivals."
