The three-time Ballon d'Or winner is set to miss most of the rest of the season because of the injury she suffered on Sunday while training with the Spanish national team.
"The expected recovery time will be around five months," said Barcelona in a statement.
Spain face Germany later Tuesday in the women's Nations League final second leg, where they aim to defend the trophy they won in 2024.
Bonmati will leave a big gap to fill for club and country in the months ahead.
Spanish champions Barça lead the league by six points from Real Sociedad, while they are joint top of the Champions League league phase table with French giants Lyon.
If Bonmati recovers on schedule, she could return for a potential Champions League final in Oslo on May 23rd, 2026.
Barcelona have reached the last five Champions League finals, winning three but losing against Arsenal in the most recent.