GREEN BAY, Wis. – Andrew Luck and Aaron Rodgers are the headliners in Sunday’s game between the Indianapolis Colts and Green Bay Packers.

But when it comes down to it, the game could end up being determined by which defense is able to stop the offense led by Luck or Rodgers.

A loss will officially give the Colts their worst start under coach Chuck Pagano.

Here are three keys for Sunday’s game:

Get the ball to Gore: The Packers enter the game second in the NFL in stopping the run, allowing just 74.4 yards a game.

But that doesn't mean the Colts should immediately forget their running game. They need to do a better job of at least trying to establish their ground game after it was nonexistent against Kansas City in Week 8. Running back Frank Gore had a season-low nine attempts (for 37 yards) against the Chiefs.

Offensive coordinator Rob Chudzinski admitted they need to get the ball to Gore more.

“Absolutely,” Chudzinski said. “I think we had a number of run-pass checks where we weren’t able to get it to him early in the game. And then, obviously in the second half, it got to the point where we needed to try to throw it and not be able to get it to him the way you’d like to.”

Being able to run the ball means the Colts can eat some clock and keep Rodgers on the sideline for as long as possible.

Youth in secondary: Trying to stop Rodgers with an experienced secondary is challenging enough. The Colts are about to experience what it’s like to try to contain him with a lot of youth at safety.

Rookie T.J. Green and second-year player Clayton Geathers will be the starting safeties with veteran Mike Adams (groin) out.

Rodgers will likely use as much of his experience to his advantage to get Green and Geathers to show their hands, which in turn will play into the quarterback's hands.

“There’s nothing that Aaron has not seen, but that still doesn’t mean you don’t work your disguise,” Colts coach Chuck Pagano said. “He is going to make some plays, we know that, but we have to make our fair share and we have to try to make him go the long, hard way and not give him anything cheap, be on the same page, communicate back there. He’s tough to stop even if he doesn’t know, but if he knows, then it makes it 10 times as difficult.”

Protect Luck: Another game, another week where the Colts have to hope their offensive line can give Luck time in the pocket to throw the ball.

Pagano described the Packers’ defensive front seven as being “virtually unblockable.” That’s not good for an offensive line that will be without its starting left guard Jack Mewhort and starting right tackle Joe Reitz and after giving up six sacks against Kansas City in Week 8 to increase its season total to 31.

Jon Harrison is the frontrunner to start at left guard, with rookie Joe Haeg starting at right tackle.

Led by linebacker Nick Perry’s 5.5 sacks, the Packers have 19 sacks on the season.

“We have to protect and be able to run the football, beat man coverage, get separation in the back end and try to make some plays,” Pagano said.