Gage was injured when he fell to the ground after making a leaping catch to set up the go-ahead touchdown in last week's 34-27 road victory over the San Francisco 49ers.
Gage finished the game with a season-high 97 receiving yards, but he started hurting once the adrenaline wore off, so the Titans ran a variety of X-rays and CAT scans on him to diagnose the injury. Titans coach Jeff Fisher said Thursday that the tests revealed the multiple fractures in Gage's back.
The injury doesn't involve any structure crucial to the spine, and Gage said Wednesday that he hasn't had any problem moving his hands and feet. He watched practice Thursday but wasn't immediately available for comment in Tennessee's locker room.
Fisher didn't rule Gage out against the Bills, but the coach called it unlikely that the seven-year pro will play.
"He's obviously very uncomfortable," Fisher said. "We experienced this back a few years ago with Peter Sirmon."
A linebacker, Sirmon missed two games with a similar injury before returning in 2003. Fisher said it's the kind of injury that happens with the impact the 6-foot-4 Gage had when he slammed into the turf after going high into the air for the catch.
"It's just a matter of pain," Fisher said.
The injury likely means rookie Kenny Britt will make his first start against the Bills. The first-round draft pick out of Rutgers is the Titans' third-leading receiver with 20 receptions for 296 yards, and he's averaging 14.8 yards per catch.
Notes: Titans CB Cortland Finnegan practiced Thursday after being given a day off. DE William Hayes also got a day off Thursday. ... Rookie RB Javon Ringer, who spent a night in the hospital after hurting his back Oct. 28, practiced for the first time Thursday. ... Veteran RB LenDale White missed his second consecutive practice with an illness. RT David Stewart (hamstring) missed his third practice in a row.
Copyright 2009 by The Associated Press