Virginia Coach George Welsh generally has a policy against players losing their starting spots because of injuries. But even though his usual starting quarterback, junior Dan Ellis, has fully recovered from a concussion suffered nine days ago, Welsh said Monday he is not sure Ellis will return to the starting lineup against Buffalo Saturday because of backup David Rivers's performance in the Cavaliers' 45-38 upset of No. 7 Georgia Tech last weekend.

"I don't know what I'm going to base it on," Welsh said. "I think you have to consider the fact that [Rivers] played so well for three quarters. Quarterback is a different position. I try not to make it one, but it is."

After playing some of the best football of his short career as a starter, Ellis suffered a concussion just before halftime against No. 1 Florida State Oct. 30. Rivers, a redshirt junior, stepped in and performed adequately in the second half against the Seminoles, and started off poorly against the Yellow Jackets, falling behind 17-0.

But over the final three quarters, Rivers led an offensive surge, completing 18 of 27 for 228 yards and three touchdowns to help Virginia outscore the high-powered Georgia Tech offense, 45-21. With NCAA rushing leader Thomas Jones distracting the Georgia Tech defense, the Cavaliers' passing game threatened the secondary deep better than it had for most of its first seven games.

"I feel like I've done everything I can do," Rivers said. "It's been a long four years. There have definitely been some bumps in the road."

Ellis watched both games on the sideline in uniform. He had practiced just once the week before the Georgia Tech game and still suffered some lingering headaches. Welsh said after that game that Ellis would have played only if Rivers had gotten hurt. Before the concussion, Ellis had engineered a 10-7 halftime lead over Florida State, and was coming off a 30-point third-quarter explosion that lifted Virginia past North Carolina State, 47-26, in the previous game.

But now, Ellis has fully recovered. Buffalo, at 0-9 overall and 0-7 in the Mid-American Conference, is unlikely to test either quarterback, and Welsh is considering using both Saturday. They are listed as equals on the depth chart.

"I've always been a one-quarterback guy," Welsh said. "I think you can play two quarterbacks and still win, though."

Rivers and Ellis have fairly similar builds--Ellis is 6 feet 2, 207 pounds, and Rivers is 6-3, 219 pounds--and playing styles. Both prefer the protection of Virginia's big offensive line over rolling out. And while Rivers throws the ball harder, Ellis has a quicker release. The pass that caught the most attention was Rivers's third touchdown, a 42-yard strike to freshman wide receiver Billy McMullen.

"He threw it hard, but he had that extra half-second and a great passing lane down the middle," Welsh said. "Rivers is a little bit stronger, but it takes him a little bit longer to get rid of it, though. Once they start scouting him [it could be a problem]. Ellis gets rid of it quicker."

Welsh said in the spring Ellis did not clearly have the starting job, and Rivers, relatively unconsidered at the time, completed 10 of 21 passes for 190 yards in the spring game. Ellis completed 15 of 18 for 145 yards in the same scrimmage. But over the summer, Ellis asserted himself and won the job clearly.

"I'd be disappointed if I wasn't starting against Buffalo," Ellis said. "But I want to leave that up to the coaches. I'm just going to go out and practice hard, play my game and not worry."

Rivers was actually serving as the team's long snapper until Ellis's injury. He made three tackles on 50 special-teams plays. During the Florida State game, after going three and out on one series, he still lined up at center on the punt unit. Rivers was replaced Saturday by another backup quarterback, senior Will Thompson, and he will not snap and play quarterback in the same game.

"It was great Saturday," said Rivers, an Augusta, Ga., native who grew up a Georgia Tech fan. "It was special. It was one of the chances you dream of getting, to get it against Georgia Tech when they were ranked so high at the time, regardless of what happens if I start or not. If not, it would be cool to say I was 1-0 as a starter."