Swansea are set to be without Nathan Dyer for two months with the winger scheduled for ankle surgery.
The 28-year-old, who recently signed a new four-year contract with the Jacks, will have an operation on Monday to remove extra bone growth in his ankle.
"I am bitterly disappointed," Dyer told the official Swansea website.
"I was feeling good after completing pre-season training and being involved in the friendlies and the first three games of the campaign.
"I started to feel some pain in my ankle after returning from the training camp in America.