Thomas hurt his right ankle in Sunday's loss to the Los Angeles Rams. It is not believed to be a high ankle sprain, according to a source. But the second-year tackle still lands on IR in part because he had missed the previous game with a left foot injury that had him limping for several weeks.
Rookie wide receiver Kadarius Toney is also expected to miss some time after aggravating an ankle injury Sunday on the opening drive, leaving the Giants (1-5) even thinner after playing this past week without running back Saquon Barkley (ankle) and wide receivers Kenny Golladay (knee) and Darius Slayton (hamstring).
Thomas, the No. 4 overall pick in last year's draft, was playing his best football prior to the injuries. He now will miss games against the Carolina Panthers, Kansas City Chiefs and Las Vegas Raiders. He can return after the Giants' bye week when they play on the road against the Tampa Bay Buccaneers on a Monday night in late-November.
New York, which scrambled to fill its offensive line depth days before the season, is now without three-fifths of its Week 1 offensive line because of injuries. Center Nick Gates (leg) and guard Shane Lemieux (knee) are already out for the season.
Losing Thomas is a big blow. Quarterback Daniel Jones was hit from behind on the play immediately after Thomas exited on Sunday with Matt Peart stepping in at left tackle. It went for a sack-fumble that put the Giants in an even deeper hole.
Peart, a second-year player out of UConn, and Nate Solder are expected to serve as the Giants' starting tackles with Thomas sidelined.
The Giants also placed wide receiver and kick returner C.J. Board on injured reserve Wednesday. Board broke his arm at the end of a long kick return in the 38-11 loss to the Rams. His season is expected to be over.
They also officially signed former Pro Bowl linebacker Benardrick McKinney to the practice squad, in addition to wide receiver Travis Toivonen and tackle Derrick Kelly. McKinney will begin on the practice squad with the intention of being elevated to the active roster when he's ready.