Indianapolis Colts quarterback Carson Wentz is undergoing further tests on a foot injury that has ruled him out of participating in practice.

Wentz, who arrived at the Colts via a trade with the Philadelphia Eagles during the offseason, sustained the injury late during Thursday's session, according to reports.

The 28-year-old has endured several injury problems since making his NFL debut with the Eagles, who drafted him second overall in 2016.

Indeed, he has started all 16 games in a season just twice in his career, while inconsistent form last term saw him benched in favour of rookie Jalen Hurts.

Wentz also missed the Eagles' triumph over the New England Patriots at Super Bowl LII with a torn ACL, left to watch on as back-up Nick Foles led the franchise to glory.

Offensive coordinator Marcus Brady told the media that the Colts are still assessing the extent of the damage.

"He's with the docs, trying to figure what out the process is," he said of Wentz.

"(We are) still evaluating what the next move is, how bad it is. Then we'll go from there."

The Colts, who reached the playoffs last season, step up their preparations for the 2021 campaign next month with pre-season games against the Carolina Panthers, Minnesota Vikings and Detroit Lions.

They begin the regular season at home against the Seattle Seahawks on September 12.