A lingering sciatic nerve issue continues to keep Giants left tackle Will Beatty out of practice, and even though coach Tom Coughlin said it shouldn’t be a prolonged injury, it seems unlikely that Beatty will be able to play in the first preseason game against the Jacksonville Jaguars on Sunday.

That leaves offseason signing and longtime Seattle Seahawks lineman Sean Locklear to fill the void on Eli Manning’s blindside, but that doesn’t necessarily mean he’s the top backup at left tackle.

Because of right tackle David Diehl’s versatility -- he has primarily played left tackle during his career -- second-year tackle and rising prospect James Brewer has been primarily taking reps at right tackle, which suggests that’s where he would play if Beatty were out for an extended period of time. Diehl would presumably move over to left tackle and Locklear -- or rookie Matt McCants -- would back up both positions.

For now, though, that doesn’t seem to be an issue. Coughlin and the Giants medical staff expects Beatty to be at 100 percent once he can get past his sciatic nerve issue.

“With our rotation right now, I think they would have Sean there (at left tackle) and then McCants has been pretty solid at left now too,” Brewer told CBSSports.com about his expectations for Friday’s game in Jacksonville. “For me being at right, it’s more comfortable because that’s what I played in college and for the majority of last season's post camp. During the OTAs, I played left almost the whole time, so it wouldn’t be a big issue if I played right or left.”

The bigger story for Brewer isn’t whether he would play left or right in case of injury. Rather, the real development is that he’s ready to play at all.

Brewer was considered a project when he was drafted by the Giants in the fourth round of the 2011 draft because he was relatively new to the sport. He played only one season in high school and was big enough to play at Indiana (6-6, 330), but he was still very raw.

Exacerbating issues for Brewer was the NFL lockout, which prevented him from participating in OTAs or the rookie minicamp.

Now, though, Brewer isn’t so intimidated by the Giants playbook.

“I’m not stressing out anymore about trying to learn the plays,” Brewer said. “So I’ve been able to play faster and I’ve been able to focus on technique and things like that, as opposed to trying to cram everything into my head and take that all out onto the field.”

The Giants traditionally use the top backup at tackle as a blocking tight end in the jumbo formation, which is a role Brewer watched Stacy Andrews and Tony Ugoh handle last year.

Brewer appears to be the top reserve tackle now that he’s getting snaps as the jumbo tight end. And while he has experienced his own back issues, Brewer returned to practice on Monday and said he “definitely” expects to play on the right side against Jacksonville.

Locklear has also taken a few reps at jumbo tight end as well, but he’s primarily playing on the blind side lately. And again, that doesn’t necessarily mean he’s Beatty’s backup.

Follow the Giants and Alex Raskin @CBSSportsNFLNYG and @AlexRaskinNYC.