Reich said it's an old injury, possibly from high school, and a broken bone came loose in Wentz's foot. Wentz felt a "twinge in his foot" when he rolled out and planted to throw late in Thursday's practice, offensive coordinator Marcus Brady said Friday.
The Colts met with multiple doctors to see what the best recovery process was. All the parties involved agreed surgery was the way to go to remove the bone out of the fifth metatarsal of Wentz's foot and ensure the injury didn't return.
"I think it was a gut punch for him for about two hours," Reich said.
Reich said the reason for the wide recovery timetable is because players recover at different ranges. The team will possibly have a better understanding on Wentz's return once he starts the rehabilitation process between the two to four week range. The first two weeks after the surgery will be mainly rest.
"Knowing Carson, I'm optimistic," Reich said. "Knowing this is the type of injury you don't have to be pain-free to play in. You have to get to an acceptable level of tolerating pain and then you can start playing. That could happen early."
Dr. David Porter, an orthopedic foot specialist who works with the Colts, will be performing the surgery Monday in Indianapolis, a source told ESPN's Adam Schefter.
The Colts gave up a third-round pick in this year's draft and a conditional second-round pick (which could become a first-rounder if Wentz either plays at least 75% of the Colts' offensive snaps or plays 70% of the snaps and the Colts reach the playoffs) in the 2022 draft to get Wentz.
Wentz was benched in favor of Jalen Hurts with the Eagles last season after being sacked 50 times and throwing 15 interceptions in 12 games.
Injuries have been part of Wentz's first five years in the NFL. He suffered a season-ending torn ACL late in the 2017 season. He has played a full season just twice in his career.
The schedule doesn't do the Colts in any favors. The Colts' first five games of the regular season are against teams -- the Seahawks, Rams, Titans, Dolphins and Ravens -- that went a combined 54-26 last season, with four of them making the playoffs.
The Colts, despite knowing Wentz's injury history, lack experience at quarterback. Jacob Eason, Sam Ehlinger, Jalen Morton and Brett Hundley, whom the Colts signed Saturday, are the other quarterbacks on the roster. Hundley is the only one of the four who has attempted an NFL pass.
Eason, a fourth-round pick in 2020, will continue to receive first-team reps in practice and have a chance to start the regular season if Wentz is still sidelined.
"The job is Jacob's right now," Reich said. "He has to prove it, he knows that. Jacob's in the driver's seat."
A logical trade target, if the Colts decide to go that route, would be the Chicago Bears' Nick Foles, who is currently the third-string quarterback behind Andy Dalton and Justin Fields. Foles has a history with Reich, who was his offensive coordinator with the Philadelphia Eagles when he replaced Wentz after his knee injury in 2017 and led Philadelphia to a Super Bowl victory.
Foles said Monday that if the Bears decide to trade him he would like input on his destination. He spoke glowingly about Reich but said he isn't aware of any talks with the Colts.
"Listen, Frank Reich is one of my favorite, if not favorite, coaches of all time. He understands me as a player, he understands me as a person. I haven't had any talks with him," he said. "I'm a Chicago Bear right now. He knows me. We all watched the 2017 season and the playoffs when he changed the offense and built it around me and you all saw what happened. So he understood my mentality as a player and he was able to build it around me and put me in a successful position and my teammates.
"But that being said, they have Carson and Carson and I have a lot of history. I have a lot of respect for Carson, he's a tremendous player. He's going through a lot of adversity right now but he'll bound back. You know what, he might miss a few games but I know he'll be back out there. But we haven't had any talks and right now I'm a Chicago Bear so I'm going to keep slinging it with these third-stringers and we're going to dice 'em up."