The rest of the preseason appears to be out.
Manning said Saturday he will use the next two weeks to get healthy from offseason neck surgery, a timeline that could put his streak of 227 consecutive starts in jeopardy.
"I certainly want to be out there, and it's hard to keep track of the hours I've spent in rehab," he said. "I was short-changed a little bit by the lockout and I'm going to need every bit of the next two weeks, and then I can give you more of an update with where I am."
The only four-time MVP in NFL history spoke at halftime of Saturday's second high school football game at Lucas Oil Stadium. The annual tripleheader is hosted by the PeyBack Foundation, Manning's charity.
He underwent neck surgery in May to repair a nerve and has been on the Colts' physically unable to perform list since the start of training camp.
While Colts coach Jim Caldwell hasn't said when Manning might return to the practice field, it's clear there are concerns within the organization.
About six hours before Manning spoke, team owner Jim Irsay used his Twitter account to acknowledge there is a possibility the Colts will start the season without their No. 1 quarterback.
"We r evaluating the QB sitch,#18 healing but we must 2 b prepared 4 early season possibility without him,defense has 2 pick it up,big time!," Irsay wrote.
Manning said he was unaware of Irsay's comments because he had been busy rehabbing. He signed a five-year, $90 million contract in July after the 4½-month lockout ended.
"Bottom line, we truly do not know when he will be ready," Colts president Bill Polian told ESPN senior NFL analyst Chris Mortensen. "Once the nerves regenerate properly, he'll be ready. When that happens, he'll be ready to ramp up immediately. It's impossible to predict."
The notion of not having Manning line up behind center will undoubtedly make Colts fans cringe and, until now, seemed inconceivable.
Since being the No. 1 overall pick in the 1998 draft, Manning has started all 208 regular-season games and 19 more in the playoffs, the second-longest streak for a quarterback in league history behind only Brett Favre.
But the recovery from the second operation on his neck in 15 months, has been slower than expected.
"I have made progress, but I still have some work to do," he said. "When I'm healthy enough, I'll be able to play."
The only other time one of his starts appeared to be in jeopardy was in 2008 when Manning needed two operations to remove an infected bursa sac from his left knee. He missed all of training camp and the entire preseason, then struggled early in the regular season before winning his third MVP award.
With Manning, the Colts have been a perennial Super Bowl contender.
Without him, well, the dream of becoming the first team to play an NFL title game in its home stadium would certainly take a hit. Indianapolis will host the upcoming Super Bowl.
Backup quarterback Curtis Painter has started both preseason games and has completed 8 of 16 passes for 95 yards with no touchdowns and one interception. In Friday night's 16-3 loss to Washington, Painter managed only one first down and couldn't get the offense past its 29-yard line despite playing the entire first half.
Painter hasn't played in a regular-season game since relieving Manning in the final two games of the 2009 season -- after the Colts had already locked up home-field advantage throughout the playoffs. His career numbers are 8 of 28 for 83 yards with no touchdowns, two interceptions and a quarterback rating of 9.8.
Former Colts backup Jim Sorgi is a free agent should the team opt to sign another quarterback. Sorgi lives in Indianapolis but has not been contacted by the Colts.
He spent 2010 with the New York Giants but missed the season when he suffered a preseason injury that required surgery on a torn capsule and labrum in his shoulder. He began throwing in December but declined a one-year contract offer before training camp to rejoin the Giants.
Sorgi's agent, Matt Brei, said the quarterback was throwing "very well" during the offseason and the 6-foot-5 passer had gotten his weight to beyond 230 pounds. Sorgi had always been considered underweight in the low 200s. Brei said Sorgi's decision not to rejoin the Giants was personal and had nothing to do with any medical issue.
Another veteran quarterback that is available is Kerry Collins, whom Polian drafted as a first-round pick in 1995 with the Carolina Panthers. The Colts offered Collins a backup quarterback position in 2006 but he chose the Titans because of a better opportunity to play.
Irsay quickly dispelled one possible move. The Colts won't select former Ohio State quarterback Terrelle Pryor in Monday's supplemental draft.
"Not taking Pryor...what VET QB would u vote 4 to sign that's out there? If sum1 has 2 hold the fort early season,who u going with?" Irsay wrote.
But with only three weeks left until the opener, almost anybody the Colts bring in would have to learn on the fly. The Colts rely on lots of calls at the line with Manning, which is why they have traditionally relied on their own experienced quarterbacks, such as Painter and former Colts player Jim Sorgi, to fill in when Manning is not on the field.
When could Manning return?
The Colts aren't saying.
During a conference call with reporters Saturday, Caldwell reiterated the point he's made since the Colts held their first training camp practice on Aug. 1 -- it's up to the doctors.
"He's still caught in the same rehab mode, working extremely hard, as hard as he possibly can," Caldwell said. "The doctors, as of today, have not released anything."
Indianapolis had a practice scheduled for Friday afternoon but it was closed to reporters.
Afterward, Manning sped over to the Colts' home field for the prep games. He wore an orange and white striped shirt, jeans, and a baseball hat. He shook hands with students and school administrators, and even heard his name chanted.
The quarterback for Bishop Chatard wore a blue and white jersey with the No. 18, prompting some to wonder when they'd see the famous No. 18 back on the field at Lucas Oil Stadium.
"It reminds me of how fortunate we are to play this game," Manning said. "(The high school players) play this game because they love it, and I play because I love it."
Information from The Associated Press and ESPN senior NFL analyst Chris Mortensen was used in this report.