Barcelona say coach Tito Vilanova will miss a key domestic cup clash with Malaga on Thursday as he undergoes treatment for cancer of the salivary gland.
"The coach, who is following his recuperation treatment, will not be present for the match against Malaga," a club spokesman said.
Barcelona-based sports paper El Mundo Deportivo said Vilanova was flying immediately to New York for treatment of the cancer and would be away for at least 10 days.
The 44-year-old coach saw specialists in New York earlier this month.
Vilanova is undergoing chemotherapy and radiotherapy following a December 20 operation on a salivary gland called the parotid. He had a similar operation a year earlier but tests showed the cancer had returned.
Barcelona assistant coach Jordi Roura will be in charge on Thursday when they host Malaga for the return match of the King's Cup quarter-finals after only managing a 2-2 draw away in the away leg.