Colts offensive coordinator Marcus Brady told reporters Friday that Wentz felt a "twinge" in his foot when he rolled out and planted to make a throw late in Thursday's practice. He was held out for the final period of that practice due to the ailment.
"He got hurt during a team period when he was rolling out," said Brady, who spoke to the media in place of head coach Frank Reich, who is out due to COVID-19. "Planted to go throw and felt a little twinge in his foot.
"... He's been with the docs. They're trying to figure out what the process is. They're still evaluating what the next move is, how bad it is, and then we'll go from there."
League sources told ESPN and NFL Media that Wentz is set to meet with noted foot specialist Robert Anderson to gather more information about the injury. According to the outlets, the Colts hope to have a better idea of a timeline after Anderson reviews the scans.
Wentz is expected to miss the remainder of the preseason because of the foot issue, according to NFL Media, but ESPN reported that Indianapolis doesn't consider it to be a season-ending injury.
The Colts acquired Wentz from the Philadelphia Eagles during the off-season, reuniting him with Reich. The Eagles received a third-round pick in this year's NFL Draft and a conditional second-round choice in the 2022 draft for the 2017 Pro Bowl quarterback.
The 28-year-old Wentz was benched in favor of Eagles rookie Jalen Hurts last season after being sacked 50 times and tossing 15 interceptions in just 12 games.
Wentz, who suffered a season-ending torn ACL late in the 2017 campaign, has played a full NFL season only twice in his career.
With Wentz sidelined, second-year quarterback Jacob Eason took the starter's reps during Friday's practice. Rookie signal-caller Sam Ehlinger served as the backup.