INDIANAPOLIS – Shaquille Leonard’s off-again, on-again, off-again season is off again.

The Indianapolis Colts have placed their All-Pro linebacker on the injured reserve list, according to a source with knowledge of the situation. That means Leonard must miss at least four games, but it could result in him missing the remainder of what has been a frustrating season.

To this point, he’s been on the field for a total of 74 defensive snaps in three games.

Leonard suffered a setback in Wednesday’s practice and did not practice Thursday or Friday. He underwent a magnetic resonance imaging scan, and the decision was made to place him on IR.

During his normal Thursday meeting with the media, Leonard seemed to more reserved than usual. He also admitted he’s still having trouble with the nerves in his left leg and calf.

“It’s still not there,’’ Leonard said. “The nerve still isn’t firing.’’

That was the overriding issue with Leonard in the offseason, and he underwent surgery in June that addressed two disks in his back that were pressing on nerves and impacting his left leg and calf. He spent training camp on the physically unable to perform list (PUP), was added to the active roster at the start of the regular season and made his first appearance in the week 4 loss to Tennessee.

However, against the Titans, he suffered a concussion and a broken nose on a collision with teammate Zaire Franklin. That forced Leonard to miss three more games.

Athletic trainers look at injured Indianapolis Colts linebacker Shaquille Leonard (53) on the field during an NFL football game against the Tennessee Titans, Sunday, Oct. 2, 2022, in Indianapolis. (AP Photo/Zach Bolinger)

He came off the bench in the last two games, handling 24 plays against Washington and 34 at New England.

As he worked his way back, Leonard believed he was making progress.

“Each week I feel better,’’ he said. “Starting from my first day of practice, being really stiff, can’t move. And then in the game was stiff.

“And in the past two games, I see myself moving around better.’’

Wednesday’s practice proved otherwise.

In his three games, Leonard has 11 tackles, including eight solos, one interception and one pass defended.

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You can follow Mike Chappell on Twitter at @mchappell51.