Busquets has been a seemingly irreplaceable presence in Barcelona's midfield with more than 500 matches in a career that has included three Champions League titles and eight Spanish league championships.
No other player at Barcelona has matched his ability to singlehandedly hold down the midfield as the first line of defense, sweeping up balls and tackling opponents while remaining unflappable under intense pressure.
But the 31-year-old Busquets has reached the point in his career where he may no longer be a fixture of Barcelona's starting 11 against the biggest opponents.
Trailing a goal to Inter Milan on Wednesday in the Champions League group stage, Valverde made the surprise move of removing Busquets and sending on Arturo Vidal. The move paid off when Vidal's pass was blasted in by Luis Suárez, who scored again in the 2-1 win.
Valverde doubled down on that change Sunday night at Camp Nou, when he left Busquets on the bench while starting Vidal in a 4-0 Spanish league win against Sevilla.
Vidal came through even more this time, providing muscle and hustle in the midfield and scored a goal which helped to put the result beyond doubt before halftime.
His inclusion in the starting 11 meant Frenkie de Jong shifted back into Busquet's holding position. De Jong worked hard to do his best Busquets imitation, thrilling the crowd with a fancy spin move to escape two defenders and keep possession.
Busquets came on as a substitute in the second half with the game wrapped up.
The 32-year-old Vidal joined Barcelona before last season from Bayern Munich. The Chile midfielder has won league titles with Bayern in Germany, with Juventus in Italy, and in Spain last season.
"I would have liked to play more games, but we have a lot of midfielders," he said. "I am here to do my part, to be important, to help the team at every moment, and fortunately I was able to score today."
Valverde also left Antoine Griezmann on the bench after he had started every game since joining Barcelona from Atlético Madrid last summer. Griezmann has scored three times but otherwise has seemed out of sync with his teammates for long stretches of games.
Ousmane Dembele took his place and scored before the break. He was later sent off with a direct red after saying the referee was "very bad." That means Griezmann will likely be back next round.
VAR DISPUTE
Leganés club president Victoria Pavón has asked for her club's match against Levante on Saturday to be replayed after a dispute regarding the league's VAR.
Pavón claimed that "we know the VAR was not working correctly" during Leganés 2-1 home loss. Her club said it had knowledge that the video review booth was not able to communicate with on-field officials after a penalty was awarded to Levante when Dimitrios Siovas fouled Roger Martí.
The league issued a statement saying that Pavón was incorrect and that "there was no technical problem with the VAR during the (penalty) in the 44th minute." It added that it would make the video and audio from the VAR available for both clubs to consult.
Replays on television appear to clearly show that Martí was outside the area when fouled.
This is the second season that the Spanish league has used video review.
DEATH THREATS
Valencia says it has contacted police to report death threats received by club president Anil Murthy via his mobile phone.
Valencia's fans have been angry at the club and owner Peter Lim for firing successful coach Marcelino García Toral last month due to a disagreement over the lack of signings in the offseason.
Many fans attending Valencia's 2-1 win over Alavés on Saturday loudly jeered Lim and Murthy.
Murthy replied by holding a finger up to his lips and pointing to the field.