Sevilla midfielder Piotr Trochowski is expected to be out for approximately eight months after undergoing knee surgery on Monday.

Trochowski underwent a three-hour operation at the Vail Valley Medical Center in the United States to repair damaged cartilage in his right knee, an injury he sustained during the first half of Sevilla's La Liga loss to Barcelona three weeks ago.

"The operation has gone as planned and, if there are no complications, the recovery period is estimated at around eight months," the club said in a statement.

The 28-year-old German international will remain under observation in the United States for one month before returning to Spain to continue his recovery.