The Denver Broncos signed veteran running back Latavius Murray off the New Orleans Saints' practice squad on Tuesday and placed starting running back Javonte Williams and starting outside linebacker Randy Gregory on injured reserve.

It's unlikely that Murray will play this Thursday night against the Indianapolis Colts, a source told ESPN, confirming multiple reports.

Williams, the Broncos' leader in carries and rushing yards, will miss the rest of the season because of a right knee injury suffered on the Broncos' first play of the second half in Sunday's 32-23 loss to the Las Vegas Raiders, coach Nathaniel Hackett announced Monday. Sources told ESPN that Williams has a torn ACL and LCL.

Gregory will miss multiple weeks, also because of a right knee injury suffered in Sunday's loss, Hackett said. Gregory's ACL is intact, Hackett said, but Gregory will undergo arthroscopic surgery to trim his meniscus and the joint will be examined again during the surgery, sources told ESPN, confirming a report by NFL Network.

Gregory, who signed a five-year, $70 million contract this offseason, is expected to miss between two to six weeks, depending on his recovery, a source told ESPN's Adam Schefter. By going on IR, Gregory will have to miss a minimum of four games.

Murray played last Sunday for the Saints in their 28-25 loss to the Minnesota Vikings in London after being elevated from the practice squad. He rushed for 57 yards on 11 carries and scored a touchdown.

Mike Boone replaced Williams in the Broncos' lineup right after Williams went down. Melvin Gordon III had split time with Williams over the first three games of the season, but Gordon fumbled in the second quarter and the Raiders' Amik Robertson returned it 68 yards for a touchdown.

It was Gordon's fourth fumble of the season -- the Broncos have lost two of them. Gordon got only two additional carries in Sunday's game.

Murray, 32, has rushed for 5,539 yards and 50 touchdowns in nine NFL seasons. He also has 196 receptions for 1,377 yards and two touchdowns catches.

ESPN's Jeff Legwold contributed to this report.