Wentz felt a "twinge in his foot" when he rolled out and planted to throw late in the practice, offensive coordinator Marcus Brady said Friday.
Wentz is still awaiting more information from testing and and the team hopes to have a better idea of how long the quarterback will be sidelined after foot specialist Robert Anderson reviews the scans, a source told ESPN's Adam Schefter.
The Colts do not consider this to be a season-ending injury, a source told ESPN.
"He's with the docs, trying to figure what out the process is," said Brady, who was speaking to the media in place of coach Frank Reich (COVID-19). "Still evaluating what the next move is, how bad it is. Then we'll go from there."
The Colts acquired Wentz during the offseason and reunited him with Reich by giving the Philadelphia Eagles a third-round pick in this year's draft and a conditional second-round pick in the 2022 draft.
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 Colts can't afford for Wentz to miss significant time because they lack experience at the quarterback position after deciding not to re-sign Jacoby Brissett.
"He's getting better every day," Brady said about Eason. "Biggest thing, we want to continue getting him reps."
To add to Wentz's injury, Brady said Pro Bowl center Ryan Kelly could miss a couple of weeks after hyperextending his left elbow when he accidentally collided with running back Marlon Mack. Danny Pinter worked with the first unit at center.