UPDATE: The Vikings confirmed Sunday that Childs suffered a torn patellar tendon in his right and left knees. The team also said he is expected to have them surgically repaired within the next few days.
Childs -- who made a sensational leaping catch at Friday's practice -- was going high for another deep ball Saturday when he came down badly on both legs. According to an ESPN 1500 story, Childs was screaming out in pain as trainers tended to him. He was carted off the field to undergo an MRI, but his knees were too swollen for the test.
The fourth-round draft pick out of Arkansas also tore a patellar tendon during his college career in 2010.
"Tough," Vikings quarterback Christian Ponder said. "I don't know what happened, but obviously, he was holding his knee. So, that's never a good thing. It's unfortunate. We saw some of those plays that he made a couple days ago."