49ers rookie WR A.J. Jenkins will play a factor in the game plan moving forward. (US Presswire)

For most of the season, it was assumed first-round pick A.J. Jenkins’ impact on the 49ers would be minimal. It became clear early on the team’s plan for his rookie season was to include a lot of time on the sidelines, watching and learning -- a redshirt season so to speak.

With the season-ending knee injury to Mario Manningham on Sunday -- coupled with Kyle Williams’ nearly identical injury from a few weeks prior -- that plan is out the window.

For Jenkins, the future has arrived. He’ll be thrust into the game plan for the first time this season Sunday when the 49ers host Arizona with a chance to lock up the NFC West title in the regular-season finale.

“Some players get thrown into that fire and aren’t ready,” Jenkins said. “Some players can wait and then go out and have a great career.”

He’s been active in three games, but Jenkins has yet to see a pass thrown in his direction. This comes after caching 90 passes for 1,276 yards in his senior year at Illinois, where he had more than 1,000 more receiving yards than Illinois’ next best receiver.

If everything goes to plan, he'll be targeted Sunday.

“I know everyone is making it a big deal,” Jenkins said. “I’m going to be catching my first pass and everything and going to go out there and play football and do what I do best.”

Coach Jim Harbaugh indicated the team would look to the practice squad to fill the opening on the 53-man roster vacated by Manningham’s injury and that spot would likely go to a receiver, which would imply either Ricardo Lockette (6-2, 211) or Chad Hall (5-8, 187).

“They told Ricardo and I to be ready,” Hall said. “'It’s probably one of ya’ll that’s going to be up this week.' They’ve definitely hinted at it, but you just take it like I do every other week and prepare the same and always be ready.”

Hall finished each of the past two seasons on the Philadelphia Eagles’ active roster, while Lockette appeared in two games for Seattle last year.

“They just said be ready for this week. So we’ll kind of wait until the end of the week,” Lockette said. “I’ll just prepare the same as I do every week. Just be ready to play.”

Both players said they were comfortable in the offense despite joining the team after training camp.

“You have to go through meetings and you have to study your playbook every week just the same as everyone else,” Lockette said. “The scout team stuff comes out here (on practice field) just reading the cards and stuff. Other than that you have to prepare as well as Crabtree or Randy.”

This week, Lockette will play the part of Larry Fitzgerald in practice.

As he does with all his teammates, quarterback Colin Kaepernick sent praise in both players’ direction.

On Lockette, Kaepernick said: “He’s another great receiver, great target, very aggressive to the ball, a lot of great speed.”

And on Hall: “He’s a great receiver. He has a great understanding of the game. He’s very quick. He knows how to get open.”

Injury report: Tight end Vernon Davis (concussion), DL Justin Smith (elbow) and LB Tavares Gooden (ribs, illness) did not practice Wednesday. Smith is not expected to play against the Cardinals, but Davis and Gooden are expected to be available.

LB Ahmad Brooks (shoulder), CB Tarell Brown (shoulder, knee), LB Clark Haggans (shoulder), RB Bruce Miller (shoulder), CB Carlos Rogers (knee, toe), LB Aldon Smith (shoulder) and DT Will Tukuafu (neck) were all limited in practice.

LB NaVorro Bowman (wrist, shoulder), RB Frank Gore (knee), G Mike Iupati (shoulder), S Trenton Robinson (finger) and S Donte Whitner (knee) were all full participants, but listed on the injury report.

Nine 49ers selected to Pro Bowl: DL Justin Smith, OLB Aldon Smith, FS Dashon Goldson, SS Donte Whitner, ILBs Patrick Willis and NaVorro Bowman, LT Joe Staley, LG Mike Iupati and RB Frank Gore were named to the Pro Bowl. Read more about their selections here.

Follow 49ers reporter Kyle Bonagura on Twitter @CBS49ers and @KyleBonagura.