Chargers OLB Jarrett Johnson is quetionable for Sunday's game. (US Presswire)

The Chargers' injury concerns for this Sunday’s game against the Bengals (6-5) grew on Friday when OLB Jarrett Johnson (back) missed practice.
Johnson is officially listed as questionable, but may be a lot closer to doubtful. He was only limited on Thursday before missing practice on Friday.
San Diego will already be without key play makers, ILB Donald Butler (groin) and S Darrell Stuckey (hamstring) are listed as out.
Butler has been a standout on defense with 72 tackles (48 solo and 24 assists), two sacks, three pass defensed, one INT, one TD and two forced fumbles.
Stuckey is a legitimate Pro Bowl candidate for his performance on special teams with 12 tackles (10 solo and two assists), two forced fumbles and two fumble recoveries.
Brown weighs risk vs. reward: The Chargers offense is a disappointing 24th overall. A battered O-line is largely responsible for the decline, but lack of production from wide receivers share in the blame. San Diego has gotten very little out of free agent additions WR Robert Meachem (Saints) and WR Eddie Royal (Broncos). Meanwhile WR Vincent Brown has missed the entire season with a broken ankle.
Brown became the first NFL player placed on the new reserved-injured designated to return list after he suffered the injury during the second preseason game. Brown, a second year player, was described by his teammates as the Chargers best route runner at the time of the injury. Now he has been relegated to the sidelines watching his team lose six of the last seven.
The Bolts had a legitimate chance to win five of those games and Brown can’t help but think the outcomes would have been different if he had played.  “That is the worst part with any injury,” Brown said. “You always want to help contribute. Just watching this season, of course you learn a lot, but it is always a big difference setting on the sideline and not being able to get with your teammates and help in a tough situation.”
Things took a positive turn a few weeks ago when Brown started to work out on the side field. He appeared to have his best day yet on Wednesday, “It pretty much was,” Brown said. “It felt really good. Just being able to cut and get around the cones
Coach Norv Turner said he is weighing the pros and cons of Brown playing this season.
Brown understands he needs to be 100 percent when he returns because running routes and heavy running in general poses risks. “If I come back too early and it is not where it needs to be strength-wise I could risk another injury and being out another long period of time.”
Fortunately, Brown did not suffer any ligament damage at the time of the break, but the ligaments weakened without activity while the bone healed. “When you have been setting for a period of time and when you have surgery on it, it weakens a lot of places in your ankle,” Brown said. “You pretty much have to rebuild the entire thing. That’s what’s been the whole process for me.”
Whether the Chargers are in playoff contention or not will likely weigh heavy on Turner’s decision to bring Brown back this season.
New LS Nelson fits right in: LS Kyle Nelson was signed a week ago when LS Mike Windt (broken wrist) was placed on the reserved-injured list. Nelson had a solid first game against the Ravens (9-2) last Sunday. P Mike Scifres had nine successful punts and K Nick Novak made both field goals he attempted. “As long as you don’t notice me I am doing a good job,” Nelson said.
Novak previously had described Windt as the best long snapper he had worked with. “I really couldn’t tell the difference between Mike and Kyle, so that’s good” Novak said. “[Nelson] is great. He’s prepared. He’s a mentally tough guy. He didn’t seem rattled at all. I was really happy on how he handled himself on game day and how he performed.”
Nelson was pleased with Novak’s evaluation. “That’s a huge compliment because Mike is a great snapper.” Nelson said. “[Windt] was also on the sideline during the game and he was helping me; kind of telling me where my snaps were and give me little pointers. That’s huge. I don’t think you get that from a lot of people. That was really nice.”
Injury Report: Out: ILB Donald Butler (groin), WR Royal (hamstring) and S Stuckey (hamstring). Doubtful: TE Dante Rosario (hamstring). Questionable: Johnson (back). Probable: WR Danario Alexander (thigh), OLB Antwan Barnes (hamstring), RT Jeromey Clary (thigh), OLB Larry English (calf), DE Corey Liuget (tibia) and FS Eric Weddle (concussion).
Game Preview from a Chargers perspective: Chargers Game Preview vs. Bengals: Analysis, prediction, TV info
Game Preview from a Bengals perspective: Bengals Game Preview vs. Chargers: Analysis, prediction, TV info
Follow Chargers reporter Dan McLellan on Twitter @CBSChargers and @sandiegosports