Thornton was suspended for 10 weeks by the NFL for an undisclosed reason, Field Yates of ESPN reports.
Thornton was most recently waived by the Giants following their Week 14 loss to the Cowboys. It is unclear what he is being disciplined for, but his suspension will not begin until he is picked up by another squad.
Thornton was waived by the Giants on Monday.
Thornton signed with the Giants in late November but was a healthy scratch for both of the games he was with the team. He'll be free to sign with another club if he clears waivers.
The Giants signed Thornton to a contract Wednesday, Michael Eisen of the Giants' official site reports.
Thornton assumes the roster spot of cornerback Janoris Jenkins (ankle), who was placed on injured reserve after undergoing season-ending surgery Wednesday. A third-round draft pick of the Lions in 2014, Thornton has appeared in 23 games with Detroit over parts of the last three seasons, producing 28 total tackles and one sack. He'll serve in a depth role along the defensive line in New York.
The Lions waived Thornton on Tuesday, Michael Rothstein of ESPN.com reports.
The timing of Thornton's release is somewhat curious, given that he had practiced with the Lions on Tuesday and was fully expected to play Thursday against the Vikings. Evidently, the Lions felt the defensive tackle's roster spot would be put to better use by another player. Thornton appeared in four games for the Lions this season, logging four tackles and no sacks.
The Lions officially activated Thorton (suspension) on Monday, Kyle Meinke of MLive.com reports.
Thorton, fresh off serving a six-game suspension, is a welcomed addition to a defensive-tackle rotation that was thin on depth following the loss of Haloti Ngata (biceps). While he could be in store for a handful of reps right off the bat, Thornton is unlikely to warrant IDP consideration at any juncture the rest of the season.
Head coach Jim Caldwell indicated that Thornton, whose six-game suspension ended after Sunday's game, isn't guaranteed to be added to the active roster, James Hawkins of the Detroit News reports.
Thorton has officially satisfied the six-game suspension he was handed in June for a violation of the league's substance-abuse policy. While one would think his return would be welcomed after starting defensive tackle Haloti Ngata (biceps) was placed on injured reserve last week, it's apparent Caldwell may have other plans in mind.
Thornton has been suspended for the first six games of the regular season for violating the league's substance abuse policy, Tim Twentyman of the Lions' official site reports.
Thornton will be eligible to return to the active roster Oct. 16, which happens to be the beginning of the Lions' bye week. The reserve defensive lineman took 307 snaps on defense last season, racking up 19 tackles and one sack through 13 contests. With Thornton sidelined, the Lions may opt to bring in another defensive tackle to bolster the depth chart behind starters Haloti Ngata and A'Shawn Robinson. Thornton is allowed to take part in offseason practices and preseason games.
Thronton signed a two-year contract with the Lions on Tuesday, Dave Birkett of the Detroit Free Press reports.
Thronton was set to be a restricted free agent, but the Lions opted to re-sign him prior to free agency commencing. The defensive tackle recorded 13 tackles, a sack and a forced fumble in 13 games during the 2016 season. He projects to provide depth along the line heading into 2017.
Thornton (coach's decision) is inactive for Monday's game against Dallas.
Thornton missed practice on Thursday due to illness but was able to participate in full on Friday and Saturday. With every defensive lineman healthy this week, Thornton was simply the odd man out at the bottom of the depth chart. He'll have a chance at playing next week against the Packers with the division title on the line.
Thornton (foot) is listed as inactive Thursday against the Vikings.
Missing his first game of the season, the quick turnaround for the Lions' annual Thanksgiving showdown was likely the impetus for this decision. Thornton's allottment of snaps will likely be split between A'Shawn Robinson and Stefan Charles.
Three injured players have been placed on the inactive list by the Patriots for their season opener Thursday night against Pittsburgh. They are running back Travaris Cadet (hamstring), defensive lineman Trey Flowers (knee) and safety Tavon Wilson (quad).
The healthy inactives are offensive lineman Ryan Wendell, defensive lineman Khyri Thornton, linebacker Rufus Johnson and cornerback Justin Coleman.
The Packers have placed the following players on the injured reserve list Saturday: Tackle Aaron Adams, linebacker Nate Palmer, tight end Jake Stoneburner and defensive tackle Khyri Thornton.
Packers defensive tackle Khyri Thornton was forced out of Thursday's exhibition finale against the Chiefs with a hamstring injury. He was ruled out for the remainder of the game, leaving his status uncertain for the season opener.