INDIANAPOLIS -- It's official: Andrew Luck will be the No. 1 choice in Thursday night's NFL draft.

Rather than keeping the NFL's worst-kept secret under wraps until Luck's name rolled off the lips of commissioner Roger Goodell, general manager Ryan Grigson decided there was no reason to delay the inevitable: Luck will become the successor to Peyton Manning as Indianapolis' quarterback and the new face of the franchise.

"We didn't see the point in prolonging what the world already knows," Grigson told reporters Tuesday after a voluntary minicamp workout. "It's about Andrew and we wanted to do the right thing by him."

The decision is no surprise. Last Wednesday, Grigson said the Colts had made a decision about whom to take with the first choice but declined to say whether it would be Luck, the Heisman Trophy runner-up, or Robert Griffin III, the Heisman winner.

But league sources told ESPN NFL Insider Adam Schefter that the Colts had informed Luck he would be their choice to succeed Manning.

The Washington Redskins will take Griffin III with the No. 2 pick in the draft, according to league sources.

And the Minnesota Vikings, picking at No. 3 overall, have reportedly narrowed down their list of choices to three players: USC left tackle Matt Kalil, LSU cornerback Morris Claiborne and Oklahoma State wide receiver Justin Blackmon.

Grigson said last week that the team made its decision a couple of weeks earlier and that was one reason the Colts didn't have Griffin come to Indy for an interview.

The Stanford quarterback plans to have his entire family in New York on draft night. He'll fly to Indianapolis on Friday, where he will take questions from local reporters and then meet fans at Lucas Oil Stadium, his new home field.