Badosa advanced after beating 2018 finalist Sloane Stephens of the United States 6-4, 4-6, 6-2.
The Barca boss is unlikely to make many changes to the team that defeated Villarreal, partly because he has no alternatives at right back or central defense, where Sergi Roberto, Clement Lenglet and Gerard Pique currently have few options other than to continue.
"At the beginning, it's never easy, especially at the beginning of a new tournament. It's the first time for me here at Roland-Garros," the 19-year-old said.
Alcacer then showed neat footwork halfway through the second half to ensure the points for Villarreal and leave Alaves in trouble.
In Wednesday's other quarterfinals, Jiangsu smashed Sichuan 3-0 (25-8, 25-15, 25-20), Tianjin crushed Zhejiang 3-0 (25-15, 25-15, 25-22), and Shandong beat Fujian 3-0 (25-15, 25-20, 25-19). Enditem
"It's always the same old story," the football magazine kicker commented.
Liaoning followed Zhejiang tightly in the fourth set until Zhejiang strengthened the lead by scoring four points in a row. Wang Na took the set point with a service, then Liaoning gifted the victory to Zhejiang with a spiking error.
Atletico Madrid were unable to repeat the performance that gave them a 6-1 win over Granada at the weekend, as they were held 0-0 away to recently promoted Huesca.
Pakhtakor defeated Iranian team Esteghlal to reach the round of eight, while Persepolis edged Al Sadd of Qatar.
Brazil has the world's second-highest COVID-19 death toll behind the United States, with more than 141,000 fatalities. Enditem
Lincoln put the hosts ahead with a low strike after a counter-attack in the 26th minute and Fiorentina loanee Pedro capitalized on Gabriel Barbosa's unselfish slide-rule pass to double the lead on the half-hour mark.