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The last time Shaun Hill got extensive playing time was in 2010, when Matthew Stafford went down in the Detroit Lions' opener. The veteran quarterback is set to replace another high-profile starter, stepping in for Sam Bradford with the St. Louis Rams.

Predictions of a breakthrough season took a serious hit when Bradford tore his left ACL for the second time in nine months in the third preseason game at Cleveland. One betting service, Bovada, knocked down the over-under on total wins from 7.5 to 6.5.

Since the injury, coach Jeff Fisher has projected total confidence in the 34-year-old Hill, who threw just 16 passes the previous three years in Detroit and none at all last year, running the offense for the long haul.

Whether he'll be holding a clipboard or barking out signals, Hill always gets ready to start.

"I've said this plenty of times, but I've always kind of tried to take that same mindset as if I was going to be playing," Hill said after practice Wednesday. "That's the only way I know how to prepare."

The shock of losing Bradford again, Fisher said, lasted just a few days.

"There's nothing Sam was doing," Fisher said, "that Shaun can't do. We've committed to Shaun for the year."

Hill and the rest of the starters were held out of the preseason finale after five starters were injured in Week 3. Of the four others, only cornerback Trumaine Johnson remains sidelined, likely out the first month with a knee injury.

The Rams claimed another quarterback with starting experience, Case Keenum, on waivers from the Texans this week. Austin Davis remains the backup, while Keenum takes a crash course on a new playbook.

"It's like speaking a different language," Keenum said. "I'm trying to learn another language as fast as I can."

Hill's arm is not as strong as Bradford's, but he's not worried about style points heading into Sunday's opener against the Minnesota Vikings. Like Minnesota's Matt Cassel, Hill has built a pretty nice career after entering the NFL as a fringe prospect.

"He gets it where it's supposed to be so we can make plays," wide receiver Kenny Britt said. "As wide receivers, our job is to make the quarterback look good.

"I'm excited about what we're doing with this offense."

Cassel was seventh-round pick and Hill was undrafted out of Maryland, beginning his career in Minnesota in 2002. Hill didn't play at all his first three seasons and made his debut in the 2005 finale, kneeling down to kill the clock in a victory over the Bears, and made his first career start in 2007.

"You've got a bond right there, staying in the league for a while," Cassel said. "I wish him nothing but success, except for when he plays us."

Hill is set for his second career opening start, and first since '09 with the 49ers.

"It's a matter of reps. He's taken all the reps since we got back from Cleveland and so he's got a good feel," Fisher said. "He's got a good feel for what he's doing."

The Rams were going to be run-first before Bradford was hurt with the trio of Zac Stacy, Benny Cunningham and rookie Tre Mason so they're not as likely to dump it all on Hill's shoulders.

Drafting Greg Robinson No. 2 overall and re-signing guard Rodger Saffold to a free-agent deal fortified the line. Robinson has perhaps been held back by learning guard and tackle in training camp and won't start in the opener with Davin Joseph getting the call at right guard.

"We made the decision that in the opener we're better off going with experience," Fisher said. "He's going to be an outstanding player.

"Our focus right now is putting the guys on the field that we think gives us our best chance to win right now."

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AP Sports Writer Jon Krawczynski in Minneapolis contributed to this report.

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