Without injured goalkeeper Jasper Cillessen and right back Sergi Roberto for the last two games, Barca will also be missing defenders Jordi Alba and Gerard Pique after both were hurt in Wednesday's 4-0 win over Manchester City in the Champions League.
Pique sprained his right ankle while Alba injured his left hamstring and both are out until November.
"It's always worrying when you lose players," Barca coach Luis Enrique told reporters.
Lionel Messi, though, is back on top form. The Argentina captain scored one goal after coming on as a substitute in Sunday's 4-0 home triumph over Deportivo La Coruna and then grabbed a hat-trick after starting against City.
"Messi is a special player and you can only compare him with a few," said Valencia winger Nani.
Barca are fourth, two points adrift of Atletico and Real and one behind third-placed Sevilla.
Valencia are coming off an encouraging 2-1 victory over Sporting Gijon in Cesare Prandelli's first game in charge.
Atletico followed their 7-1 hammering of Granada in La Liga with a 1-0 win at Rostov in the Champions League to make it five victories in a row and 11 consecutive games without defeat.
Diego Simeone's side, who have conceded three La Liga goals in eight matches, will again look to Yannick Carrasco when they travel to Sevilla on Sunday.
The Belgium international has scored four goals, including the winner against Rostov, and set up two more in Atletico's last two games.
Sevilla, who won 1-0 at Dinamo Zagreb on Tuesday to remain unbeaten in the Champions League, have won all of their games at the Sanchez Pizjuan stadium this season.
Real Madrid coach Zinedine Zidane is hoping Cristiano Ronaldo will put his failure to score in Tuesday's 4-0 home victory over Legia Warsaw in the Champions League behind him and find the back of the net at home to Athletic Bilbao on Sunday.
"We all want him to score and he more so than anyone," said Zidane. "I hope he scores on Sunday.
"It's true that we'll always be looking for more from him because he's Cristiano and he's aware of that."
Ronaldo has eight goals in eight appearances in all competitions this season including one in Saturday's 6-1 hammering of Real Betis.
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