Since the arrival of Hansi Flick as head coach, Torres has been heavily relied upon in the final third for the Catalan giants.
A total of six starts and four substitute outings have been made in all competitions, the versatile attacker missing just one of 11 matches.
That was a result of a sending off against Girona earlier in the campaign, yet Torres went into Sunday's La Liga clash at Alaves having completed the 90 minutes in the previous two games.
However, the 24-year-old would last just six minutes in Mendizorrotza after suffering a hamstring injury during the early stages.
What have Barcelona said?
In a statement on Monday morning, Barcelona said: "Tests carried out on the first team player Ferran Torres confirm that he has an injury to the biceps femoris muscle in his right thigh.
"His return to training will be dependent on his recovery.
"Ferran Torres started the game in Mendizorrotza against Alaves on Sunday but was forced off due to a hamstring injury after just five minutes and replaced by Eric Garcia."
While Barcelona are not back in action until they play host to Sevilla on October 20, that fixture commences their most important week of the season thus far.
Three days later, Flick's side host his former club Bayern Munich in the Champions League before they make the trip to the Bernabeu to face Real Madrid in El Clasico.
Barcelona will naturally be hoping that Torres is available to take his place in the squad, yet Raphinha could be moved back out wide to deputise for the Spain international.
What are Flick's other options?
Although Flick has had to contend with multiple injury issues this campaign, he has at least been boosted by the return of two players in recent games.
Midfielder Frenkie de Jong has made two substitute outings since recovering from a long-term ankle injury, and his return could allow Pedri to be used further forward if required.
Ansu Fati has also made three substitute appearances in all competitions, the 21-year-old's re-integration after a loan stint with Brighton & Hove Albion a timely boost ahead of a busy period of the season.