PHILADELPHIA (Reuters) - Controversial Philadelphia Eagles back-up quarterback Michael Vick is preparing for what could be his first start since he was jailed in 2007 for his role in a dog-fighting ring.

First choice quarterback Kevin Kolb suffered concussion in the Eagles' 27-20 defeat by the Green Bay Packers last Sunday and under the NFL's rules he must pass a test before he can take part in practice prior to the Sunday trip to the Detroit Lions.

Linebacker Stewart Bradley is also currently sidelined with concussion and Eagles coach Andy Reid said he and Kolb had failed tests on Wednesday.

"I'm just going to follow the doctor's testing that are taking place and follow that day by day and we'll cross that bridge down the road later in the week as far as status," he said.

"Right now Kevin is not practicing, Michael Vick is practicing and he's getting himself ready to play in that game. That's what I'm focusing in on right now and as far as the football part of it goes. On the medical side of those two players, getting better and going through the rehab that's available to them," he added.


Former Atlanta Falcons starting quarterback Vick was given an 18-month jail sentence for involvement in an illegal dog-fighting ring and after serving jail time was allowed back into the league with the Eagles.

The 30-year-old was used as an occasional back-up to Donovan McNabb last year but has risen in the pecking order since McNabb's move to the Washington Redskins.

Vick started in pre-season earlier this month but if he begins against the Lions it would mark his first regular season start since New Year's Eve, 2006, when he played for Atlanta against the Eagles.

Reid said that even if Vick started this Sunday, Kolb would remain his first choice quarterback but added he was delighted to see Vick back in contention.

"I am so happy for this kid and the progress that he's made since being incarcerated, in both life and on the football field, and he's worked so stinking hard to get himself to this position. So I don't want to slight him a lick.

"On the other hand, Kevin's the starting quarterback for this football team," he added.

(Reporting by Simon Evans in Miami; editing by Rex Gowar)