Following a test on the former Atletico Madrid man, Barcelona in a statement said that Aguero, has a tendon injury.
"Test carried out on the first team player Sergio Agüero have confirmed a tendon injury in his right calf. The player will be out of a action for around 10 weeks."
Aguero scored 260 goals in 390 appearances in his 10- year at Manchester City and is the club’s all-time leading goalscorer.
Having joined the Catalan giants on a two-year contract on 31 May, Aguero arrived at Barcelona training after winning the Copa America with Argentina in Brazil as he stressed;
"We all know that Barcelona are the best club in the world so I think I made a great decision to be here and I hope to help the team," he said after signing a two-year contract.
"Of course it is a step forward in my career and hopefully I can help the team win things. I want to play and help this squad, and if the team does it well, I will be happy individually."
Reacting to the news, Barcelona boss, Ronald Koeman expressed his disappointment with the situation.
"It's a pity that he's injured," Koeman said. "We have to wait for him to recover but it's a step backwards because he had been training well.
"He has a lot to offer."
Aguero was expected to have featured for the Joan Gamper Trophy but Doctors, however, have recommended 'complete rest and that he stays at home'.