Bubba Bolden won’t play for USC in opener; Clay Helton says there’s no timetable for his return

Last week, USC had two strong safeties competing for a starting position in Bubba Bolden and Ykili Ross. At minimum, the Trojans were going to emerge from camp with depth at the position and could figure out the starter as the season wore on.

At practice on Aug. 22, Ross lost his cool, throwing a tantrum and sitting out the rest of practice. USC coach Clay Helton said he would have a talk with him. When USC released its depth chart for Nevada Las Vegas on Sunday, Ross was not included because he had decided to focus on his upcoming graduation so that he could become a graduate transfer.

That put Bolden, the talented and brash sophomore from Las Vegas, in line to start. Bolden said Wednesday that he wanted to emerge as a leader for the Trojans and eventually be voted a team captain.

So it came as a shock after practice Thursday when Helton announced that Bolden did not practice and would not be available for the opener Saturday against UNLV at the Coliseum.

“There’s no timetable for his return, and I can’t comment further at this time,” Helton said.

Redshirt freshman Isaiah Pola-Mao will start at strong safety in his first college game. Pola-Mao and starting senior free safety Marvell Tell III will be backed up by sophomore CJ Pollard and freshman Talanoa Hufanga.

“Those guys will be able to handle it,” Helton said.

Helton said he expects Tell and Pola-Mao to play most of the snaps Saturday.

Center questionable to play

Helton said that starting center Toa Lobendahn missed his second straight practice because of a pectoral strain. Redshirt freshman Brett Neilon will start in Lobendahn’s place if he is unable to play.

“Besides Toa being questionable and not looking great, like he’s going to be there for us, we still have a two-deep that can get it done,” Helton said.

Cautious with Carr

The depth chart lists talented sophomore Stephen Carr as the third option in a running back committee with Aca’Cedric Ware and Vavae Malepeai, and Helton explained why.

“The one thing that’s just a gray area is it’s Stephen’s first game back off back surgery,” Helton said, “and we’ve had contact, he looks good, but I really want to try to get a feel for it once we get in that game. The beautiful thing is you have Ced and you have Vae who have had unbelievable camps. I’m looking not only for this game but for the extended period of time when you’re talking about hopefully 15 games that three-headed monster can roll in there.”

Etc.

Helton said left tackle Austin Jackson and outside linebacker Porter Gustin each looked ready to play Thursday. … Helton said tight end Josh Falo did not practice and is questionable because of a tight hamstring. More injuries: Palaie Gaoteote (meniscus surgery, ruled out for Saturday); Josh Imatorbhebhe (ankle rehab); Daniel Imatorbhebhe (quad rehab); Austin Applebee (mononucleosis); Jordan Austin (pectoral strain).

brady.mccollough@latimes.com

Twitter: @BradyMcCollough