Horton tweeted the news and revealed he and the organization agreed to a one-year deal:
The Panthers officially confirmed the deal Tuesday.
The 26-year-old former Southern California standout has spent the past three seasons with the Panthers, and he registered one sack in eight games and two starts in 2015.
The Panthers waived him once he became eligible to return and sent him to the practice squad, but ultimately, they decided to bring him back for the 2016 campaign in order to provide some defensive line depth.
Horton was also let go earlier in the 2015 season, but he was re-signed a few days later. Per ESPN.com's David Newton, Horton understands the business aspect of the NFL:
I didn't take it personal. It was a roster move they had to make. It felt pretty eerie on the outside, watching the guys.
The first thing after I cleared waivers they were the first ones to call. They held up what they told me when they released me, so I do feel a little wanted in that regard.
With defensive linemen Frank Alexander and Kyle Love set to hit free agency, signing Horton for 2016 provides a strong insurance policy should one or both of them end up elsewhere.
He has 44 tackles and six sacks to his credit in 34 career NFL games and should be helpful when it comes to spelling the likes of Charles Johnson, Jared Allen and Kony Ealy.
Horton won't be asked to do too much within head coach Ron Rivera's defensive scheme, but as someone who is quite familiar with it, returning him to the 53-man roster is a sensible move in an effort to get back to the Super Bowl and win it this time around.
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