Reserves catch on as injuries strike 49ers receivers

SANTA CLARA – Anquan Boldin is San Francisco’s top receiver, but who starts opposite him for the Sept. 8 opener is even more questionable as injuries mounted among the 49ers receivers at Tuesday’s practice.

Unproven 2012 first-rounder A.J. Jenkins (hamstring), and veteran special teams ace Kassim Osgood (hip) both exited and didn’t return; slot machine Kyle Williams (hamstring) sat out today and rookie Quinton Patton (broken finger) donned a non-contact jersey for the fifth consecutive day.

Would-be No. 1 and No. 3 options Michael Crabtree (Achilles) and Mario Manningham (ACL) are on the physically unable to perform list, and Brandon Carswell (ACL) is on injured reserve.

Speedy pass catcher Ricardo Lockette toughed out a hip pointer while the gutsy Marlon Moore took first team reps on a slightly sprained ankle.

Moore spent three seasons with the Dolphins; now, with so many guys hurt, he has a a chance to showcase his skills which have earned head coach Jim Harbaugh’s praise.

Moore told the Bay Area News Group’s Cam Inman about his recent shot:

“It is a big opportunity for me and every receiver. We know what’s at stake. All I can do is make plays when I get opportunities. Coaches will make the right decision on who they want.”

Chad Hall – a scrappy member of last year’s practice squad who spent time this off-season working out with Colin Kaepernick – was again recognized for stepping into the slot. The “real Swiss Army knife” — seventh-round pick quarterback, returner, and wideout B.J. Daniels – also filled in with the rest of the corps depleted.

Five-year vet Charly Martin and undrafted rookie Chuck Jacobs have moved up the depth chart temporarily with Vernon Davis and Vance McDonald remaining at tight end, and even with binoculars Austin Collie isn’t in sight at the moment.

The 49ers are counting on someone from this group of receivers to emerge as the No. 2 before their Week 1 meeting with the Packers.

Notes

Second-year linebacker Darius Fleming (torn ACL) was waived today and will land on injured reserve after clearing waivers. … The 49ers signed San Jose State defensive end Travis Johnson to a three-year deal to take Fleming’s roster spot. … Ian Williams continues to earn praise as the teams’ starting nose tackle. … Free safety C.J. Spillman again took snaps with the first unit, but he and Patrick Willis were beat for a 50-yard touchdown reception by Davis from Kaepernick.

Follow @SFBay and @drewmorita on Twitter and at SFBay.ca for full coverage of the 49ers.