The Swiss youngster looked lively until having to limp off just two minutes before half-time. He was replaced by fit-again Thimothee Atouba.
"Reto had to come off," reported Head Coach Martin Jol. "He has pulled a hamstring so that could be two weeks or it could be six weeks."
We'll bring you more news on Reto when we know more on Monday...
Reto Ziegler suffered a hamstring injury in Saturday's clash against Palace at Selhurst Park.