The Barcelona fullback underwent tests to identify the severity of the knock he suffered against Manchester City and early indications suggest he will miss the Real Sociedad game.
The 24-year-old defender played the whole 90 minutes of Barca's 2-0 victory at the Etihad Stadium on Tuesday, but now looks set to miss its La Liga clash with Real Sociedad on Saturday following tests upon his arrival back in Spain.
It is the second time this season Alba has suffered a muscle strain, as he was sidelined for more than two months with a thigh problem before the mid-season break.
Barca confirmed the news of his latest injury on its official website, with a statement reading: "After arriving at the Ciudad Deportiva (Barca's training complex) tests have confirmed that the player Jordi Alba has pulled a hamstring in his right leg. The results will put his availability for the next match in doubt."
The Spanish champions' win in Manchester puts them in pole position to reach the quarterfinals of the Champions League ahead of the second leg of their last 16 tie at Camp Nou next month.