Rivas blow leaves Betis reeling

The 24-year-old had further tests on Tuesday which revealed he would have to go under the surgeon's knife.

Rivas refused to put a timeframe on his recovery period, but club doctors expect him to be out for at least a month.

"It's been bad news for me, the injury was still causing me problems and was not improving with rest so I had the operation," said the Betis star.

"We'll have to see how I progress, but I will try to be back as soon as possible."

News of Rivas' absence will come as a further blow to Betis boss Victor Fernandez who has a host of first-teamers unavailable for his side's forthcoming league encounter with Deportivo.

Along with Rivas, Juanito, Dani, Benjamin, Ito and Alfonso have all been ruled out of the clash with injury problems, while Luis Fernandez misses the game through suspension.