Coach Brad Childress knows who will start at quarterback for the Vikings on Sunday at Detroit. He's not telling yet. Childress said Wednesday he has made a decision between veteran Brad Johnson and rookie Tarvaris Jackson, then resorted to gamesmanship when pressed about which player will be under center against the Lions. "I'm probably not going to share that with you just because I'm not competitively going to do that," said Childress. He said he has informed the quarterback he's chosen.