Fred Warner will undergo further tests to determine severity of ankle injury

49ers linebacker Fred Warner left in the first half with an ankle injury. He did not return, but Warner said postgame that he tried. "I know Fred tried to go, came out in third quarter and tried to go, but didn't feel like he could," coach Kyle Shanahan said, via David Bonilla of 49erswebzone.com.Shanahan provided no specifics about the severity of the injury, but Warner will undergo an MRI on Monday."I would have been out there if I could have been," Warner said. "We'll see as we get more information on it. . . . If I could have been out there, I would have been. We'll get more information as we go, with scans and all that, but I feel good right now."Warner had seven tackles and a 45-yard interception return for a touchdown.Shanahan expressed cautious optimism that defensive tackle Jordan Elliott, who exited with a knee injury, does not have a significant injury."I don't think it was an ACL or anything, but it just had some swelling and stuff, so he couldn't go," Shanahan said.Fullback Kyle Juszczyk left with a shoulder injury late in the game.