Harrison missed all three practices this week because of a bruised left knee, and Dungy said Harrison and several others are expected to be game-time decisions for the contest between the NFL's final two unbeaten teams.
"Our dilemma is that the doctors thought if he (Harrison) plays, he could have continued issues with it," Dungy said Friday in his final media availability before the game. "If we give him another week off, he probably would not have the same issues down the stretch. But he wants to play."
Who wouldn't want to play in the NFL's game of the year?
But some of the players don't have a choice.
New England placed running back Sammy Morris on injured reserve because of a chest injury Friday, ending his season. Morris was hurt at Dallas.
The questions surrounding Harrison are more complex. He hurt his knee against Denver on Sept. 30. Since then, he has missed two more games and was put on a play count that limited to about only half of the Colts' plays at Jacksonville on Oct. 22.
If Harrison plays against New England (8-0), Dungy said the receiver, listed as questionable, would likely again be on a play count.
To compensate for Harrison's absence in previous games, the Colts (7-0) relied more on tight end Dallas Clark and receivers Anthony Gonzalez and Aaron Moorehead.
Moorehead and Gonzalez couldn't say whether they'll fill the same role this week after the Colts uncharacteristically closed all but the stretching exercises to local reporters.
"I'm not sure, we'll see what happens," said Gonzalez, the Colts' first-round draft pick in April. "Marvin is incredible at many things and one of those is healing."
If this was an actual playoff game, instead of merely hyped as a postseason game, Dungy said Harrison probably would play.
"He has played without practice before, and if he does play, I think he'll be pretty effective," Dungy said. "It will have to be a decision that's best for the season and not just best for this game."
Dungy may have some other tough calls, too.