The Rams’ most wide-open camp battle is taking shape.

Wide receivers Austin Pettis, Danny Amendola, Greg Salas, Steve Smith and rookies Chris Givens and Brian Quick are all but locks to make the team. Brandon Gibson and Danario Alexander have fallen behind due to leg injuries. Nick Johnson, Mike Campbell and newly signed Charles Gilbert and Brandyn Harvey are serious longshots.

Pettis, the second-year man out of Boise State, is making the most plays in practice. The 6-foot-3, 207-pounder led the team with three catches for 25 yards at Indianapolis, including a tough third-down grab to extend a drive.

“The third-down catch was a huge catch, Sam’s slant,” coach Jeff Fisher said, referring to quarterback Sam Bradford. “That was a big catch and he’s been doing that here on the practice field. So, he’s improved along with the rest of the group.”

Amendola, the slot man who made 85 catches in 2010, got his first game action in Indy since suffering a season-ending elbow injury in Week 1 last year.

“I went down the first game of the year last year, sat out the whole year and then just to get out there and run around and hit and get tackled in a real game is fun,” Amendola said.

Salas and Smith, the most experienced of the group, are reliable targets.

Givens, the fourth-round pick out of Wake Forest, is emerging as a deep threat. He drew a 54-yard pass interference flag against the Colts and would have had a long touchdown had Kellen Clemens not barely overthrown him.

"He can get deep," wide receivers coach Ray Sherman told the Post-Dispatch about Givens, who clocked a 4.39 forty at the Combine.

"He's got that kind of speed. When people see that on tape, see that he's able to run like that, then they're going to respect him. It helps everybody else because you know he can do that."

Quick (6-4, 220) is a raw talent out of Appalachian State. He’s not developing as quickly as Givens, but coaches will be patient with their second-round pick.

Gibson impressed early in camp with acrobatic catches before being sidelined. Alexander, a big-play receiver who’s never been able to stay healthy, has barely been able to suit up.

With Pettis suspended for the first two games for violating the league’s policy on performance-enhancing substances, Gibson is likely to stick as the sixth wideout unless Alexander comes back soon.

Still, all the receivers know they can’t relax. Pettis’ return in Week 3 means someone else will have to go.

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