With the Broncos quarterback position decided, the big focus in Saturday’s preseason game will now shift to the guys who can be a quarterback’s best friend.

Churn out hard yards and keep the chains moving. Break a long run and keep the defense honest. Pick up a block and give the quarterback that extra second he needs to hit a receiver downfield. These are the ways a running back can endear himself to his quarterback.

On Saturday we’ll get a glimpse of just how friendly the running back corps can be for Trevor Simian.

The Broncos believe they can be effective running the ball this season. They’ve upgraded the offensive line and are confident in the stable of backs they have at their disposal. C.J. Anderson, Denver’s feature back, is healthy after missing the second half of last season. Devontae Booker, last year’s leading rusher, is nearing a return from an offseason wrist injury. Rookie De’Angelo Henderson, who looks more like Maurice Jones-Drew with each passing day, continues to surprise.

Perhaps the best news of all, the Broncos have a potential ace up their sleeve in veteran back Jamaal Charles.

Charles’ injury history is no secret here in Denver. He missed 24 games over the past two season for Kansas City with injuries to his right knee. Now, he’s hoping to extend his career with a division rival and prove to the Chiefs that he’s as dangerous now as he ever was.

The four-time Pro Bowler and two-time first-team All-Pro will see a heavy workload on Saturday against Green Bay, his first action of the preseason.

Charles is in competition with another veteran with a knee injury in his past, Stevan Ridley, and a player who keeps finding his way onto the squad year after year, Juwan Thompson. Charles certainly has the pedigree to justify a fourth and final running back spot on the 53-man roster, but is he healthy enough?

Charles said on Tuesday he’s feeling like himself, physically.

“I feel like I’m back to my normal me. I’m back to my normal weight. Last year, I was 195. This year I’m 204, 205. I’m back to my normal weight, I’m back to [that weight] and whatever I have to do, whatever they want me to do,” he told the media.

He’s been testing out that knee, and is ready for the biggest test yet on Saturday.

“I’ve been testing it. I’ve been testing it since I’ve been doing walk throughs, I’ve been doing it since I’ve been doing off season working out without a brace,” Charles said. “I tested it today; every day is a test when you come out here. Every day is a time to get that knee in shape and the time to get your whole body in shape. It’s just time to get great in everything you do.”

Tests are all well and good, but it’s what happens on the field against the Packers that will likely determine Charles’ fate in Denver.

Head Coach Vance Joseph wouldn’t say specifically what he needs to see to know that Charles is ready for NFL action, but did say he’s excited to see Charles back on the field.

“Just Jamaal being Jamaal. It’s a big day for him and he’s excited. I’m excited for him. He’ll play well,” Joseph said.

Offensive Coordinator Mike McCoy echoed those same sentiments.

“Just go out and play. I’m really excited for him, for the opportunity,” McCoy said Wednesday. He’s worked extremely hard to get to where he is today coming off the injury that he had. We’re all excited to see him play.”

Joseph is particularly enthusiastic about what he’s seen of late from the veteran.

“He’s looked explosive for about two or three weeks now. That hadn’t changed,” Joseph said. “It’s both the needle moving, I guess. He looks explosive right now.”

Denver’s depth and variety at running back, from Anderson the bruiser to Henderson the speedster, gives McCoy options in the play calling and has the former, and now current, OC feeling confident.

“You can never have enough,” McCoy said when asked about the variety of backs on the team right now. “You want to have enough guys out there, like we’ve said from 2002-on, we’ve always played with multiple backs back there. The tempo of the game, the flow of the game, we’re going to play a number of guys. Happy with what they’ve been doing.”

The coaches are happy with the group, and with Charles. On Saturday Charles will get his shot to make his quarterback just as happy, and maybe make a new best friend.