The Chargers(4-5) received some good news on the injury front for Sunday’s critical game against the Broncos (6-3). Three starters participated in practice Friday who were either limited or did not practice on Thursday. 

RB Ryan Mathews (stiff neck) missed practice Wednesday and Thursday but was limited on Friday. “I was encouraged by watching him run around,” coach Norv Turner said. “He moved a lot better.”

Mathews is officially listed as questionable but indicated he will likely play. “[My neck] felt good,” Mathews said. “It has loosened up a lot. I felt great today.”

LG Tyronne Green and FS Eric Weddle fully participated after being sidelined with an illness Thursday.

Scifres booms: P Mike Scifres isn't 100 percent after he injured his right ankle during a blocked punt vs. the Buccaneers on Sunday. But he demonstrated in practice that he has enough leg strength to be extremely effective. He consistently made 50-yard kicks and a few traveled as far as 60 yards. 

Ayers a threat: Broncos RDE Elvis Dumervil (shoulder) is listed as questionable. Dumervil leads Broncos defenders with a career eight sacks against San Diego. This season, Dumervil has seven sacks with five forced fumbles, including two sacks and two forced fumbles of QB Philip Rivers in Week 6.

DE Robert Ayers, a first-round pick in 2009, would play in place of Dumervil. Ayers had the best performance of his career last week with three tackles (two solo and one assist), one sack and two passes defensed.

“Ayers had some outstanding rushes against us in the first game,” Turner said. “He is a good football player.”

LT Michael Harris (undrafted, UCLA) said he will need to have exceptional hand work if he faces Ayers (6-foot-3, 274 pounds) because he is bigger than Dumervil (5-11, 260). Harris will likely receive his sixth start of the season in place of LT Jared Gaither (groin, doubtful).

Gates on verge of TD record:  TE Antonio Gates (80) needs a touchdown catch to match WR Lance Alworth (81) for the franchise record. “It’s awesome,” Turner said. “To do it over a period of time and play at such a high level. To do it with so much adversity over the last three years, with the type of injuries he has had to fight, tells you what type of person and what type of player he is.” Gates has four touchdowns this season, including one in each of the last two games.

Injury Report: Out: NT Aubrayo Franklin (knee). Doubtful: LT Gaither (groin). Questionable: RB Mathews (stiff neck) and TE Dante Rosario (hamstring). Probable: OLB Antwan Barnes (hamstring), SS Atari Bigby (quad), CB Chris Carr (knee), LG Green (ribs/illness), OLB Melvin Ingram (knee) and P Scifres (right ankle).

Follow the Chargers and Dan McLellan on Twitter @CBSChargers and @sandiegosports.