San Francisco 49ers

D-line depth: 49ers NT Ian Williams ready to practice

The reinforcements are beginning to arrive.

The 49ers, who practiced with only five healthy defensive linemen in Maryland recently, on Tuesday removed nose tackle Ian Williams from the physically-unable-to-perform list.

Williams, 24, was San Francisco’s starting nose tackle early last season but suffered a nasty lower leg injury when a Seattle Seahawks offensive lineman cut-blocked him in Week 2. That type of block – from the side, with the offensive lineman rolling up the leg – will be penalized this season.

Williams underwent multiple operations on the fractured fibula and torn ligaments, and he had a setback this spring, according to 49ers defensive coordinator Vic Fangio. The team lost another nose tackle, Glenn Dorsey, for an extended period when he tore a biceps tendon in training camp.

Dorsey is a candidate to land on the injured reserve list with a designation to return during the season. The 49ers must decide whether to put that designation on a player by Sept. 2. Each team is allowed one player on that list, and coach Jim Harbaugh has said he regretted not doing so with outside linebacker Parys Haralson (torn triceps) in 2012.

Williams now becomes the favorite to start the season at nose tackle. Mike Purcell started Thursday’s preseason opener but was pushed around by the Baltimore Ravens’ offensive line, and Baltimore rushed for 237 yards. Quinton Dial and Tony Jerod-Eddie also filled in but are better suited as defensive ends. The 49ers don’t use a nose tackle when they are in their nickel defense, an alignment they’ve used on nearly 60 percent of their defensive snaps in previous years.

Two more defensive ends also are close to returning to practice, starters Justin Smith and Ray McDonald. Smith had offseason shoulder surgery; McDonald has been dealing with a minor leg injury.

“I’m thinking that those guys will be ready to return maybe when we get back to San Francisco at some point in the near future,” Fangio said Sunday during the team’s joint practice with the Ravens in Owings Mills, Md.

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