The Rams gave up an NFL-high 55 sacks last season, and coach Jeff Fisher and offensive coordinator Brian Schottenheimer have stressed that protecting Sam Bradford is their top priority.

So the fight for jobs on the offensive line is worth watching when the Rams visit Indianapolis in Sunday’s preseason opener. The team also must sort out intense battles at wide receiver and free safety.

Look for most starters to play two series to a quarter, with 29-year-old running back Steven Jackson playing less.

Questions to be answered in exhibition season:

Is time running out on Jason Smith? The No. 2 overall pick in the 2009 draft isn’t a lock to start the season opener or even Sunday’s game. Veteran Barry Richardson got first-team reps this week as new O-line coach Paul Boudreau demands improved pass protection from Smith. "His whole thing that he needs to work on the most is understanding angles in protection, understanding he has long arms but he doesn’t use them and try to get his length back in protection," Boudreau told "He wants to hit a guy all the time and you don't have to hit a guy in pass protection. You just have to stay in front of him. When he does it right, you have to really emphasize it on the tape."

Who’ll separate at wide receiver? The Rams don’t have a returning pass-catcher who finished in the top 100 in receiving yards last season. Eight wideouts are competing for a likely six spots. Slot man Danny Amendola, who had 85 catches in 2010, has been the most consistent performer in training camp, according to Post-Dispatch beat writer Jim Thomas. Steve Smith, Brandon Gibson, Greg Salas and Austin Pettis have had their moments, while Danario Alexander just returned from a hamstring injury. Rookies Brian Quick and Chris Givens haven’t had much work with the starting offense.

"It's still very fluid," Schottenheimer told the Post-Dispatch. "There's going to be a lot of combinations that you guys will see, even working through the second and third preseason game as we're just trying to evaluate everybody.

"A lot of the young guys are coming along," Schottenheimer added. "I think you see a guy like Brian Quick picking it up now. For him, third, fourth time (going through the offense) he's starting to get it."

Will the run defense finally become respectable?The Rams ranked 31st in run defense last year, allowing 152.1 yards per game. Opposing backs averaged 4.8 yards a carry. As a result, the team grabbed LSU DT Michael Brockers with the 14th pick and signed 26-year-old free agent DT Kendall Langford. With Langford back at practice Thursday after missing Wednesday’s workout due to illness, fans should get a glimpse of the new interior duo. Defensive ends Chris Long and Robert Quinn, who combined for 18 sacks last year, have looked even quicker off the ball in camp. But run defense remains the biggest concern.

Get more Rams updates and analysis from Larry Hartstein @CBSSportsNFLSTL.