The Broncos signed former Chargers running back Jacob Hester on Monday morning.Hester, at 235 pounds, becomes the biggest back on the Broncos’ roster. Hester was at the team’s Dove Valley complex Monday and will practice with the team Wednesday.

Hester started 23 games for the Chargers in his four seasons with the team, usually working out of the fullback spot. He had 94 carries split over those four years to go with 55 receptions.

Hester also could play some special teams. Denver will host the Tampa Bay Buccaneers on Sunday at Sports Authority Field at Mile High.

The Broncos had worked Hester out last week, along with former Texans running back Steve Slaton. The Broncos had only 52 players on their roster last week, including four running backs in Knowshon Moreno, Ronnie Hillman, Lance Ball and Chris Gronkowski.

Willis McGahee tore the medial collateral ligament and suffered a compression fracture of his right knee early in the second quarter of the Broncos’ 30-23 victory over the San Diego Chargers on Nov. 18. McGahee was moved to injured reserve, but has been designated to return during the playoffs.

Broncos coach John Fox has said McGahee would be sidelined six to eight weeks. The injured reserve designation means McGahee will be sidelined six weeks before he can return to practice Dec. 31, which would be the first day of the postseason.

Injured reserve designation rules would allow McGahee to play in a game in eight weeks — which would be the week of the AFC championship game.

Jeff Legwold: jlegwold@denverpost.com or twitter.com/jeff_legwold