Vikings left tackle Matt Kalil matched up against an unheralded "No. 94" on Friday.

Offensive line coach Jeff Davidson doubled as a scout team member during the walk-through period. The jersey number and a spin-move pass rush, one that resembled the quickness of a three-toed sloth, were all Davidson could do to emulate Rams defensive end Robert Quinn.

"I'm not going to give [Kalil] the true speed of what he's getting there," Davidson said. "All we want to do is work with the finer details of his trade."

It's a trade that needed to be fine-tuned during training camp and preseason for Kalil, who regressed last season as a pass blocker and will face Quinn, one of the NFL's top defensive ends, to start the regular season on Sunday in St. Louis.

Kalil said he's arrived on the field 30 minutes before practice since the start of training camp and spent the final 10 of those minutes working with Davidson on different elements of his technique.

The routine continued this week, with Davidson and Kalil even working after practice to prepare for Quinn, who finished second in the league last season with 19 sacks. The Rams finished third as a team last season with 53 sacks.

It was clear last year that Kalil, in his second season, wasn't the same player who made the Pro Bowl as a rookie. He allowed team highs in quarterback hits (12) and quarterback hurries (13) and tied for second with four sacks allowed, according to Pro Football Focus. He had offseason surgery on his right knee, which Kalil said bothered him during the year, and missed all organized team activities and minicamp.

"I think it was just being out from OTAs so much that I kind of lost my form, and it's all about refining it and getting back to where I was," Kalil said. "Now it's taking this long, but it's not as easy to come back Day 1 and be yourself again."

Kalil said he used the preseason as an experimental period, borrowing nuances from other offensive linemen in the NFL he watched on film. He settled on mimicking former Panthers left tackle Jordan Gross because of their similar sets in pass protection.

While he tinkered with his technique, Kalil's preseason performance brought flashbacks to last season. He allowed two sacks, one in the opener against the Raiders and the second in the third exhibition game against the Chiefs. Kalil was tested with good pass rushers against Kansas City that blew right by him at times. He allowed three quarterback hurries in that final preseason appearance.

"I wouldn't say I was uncomfortable, but I didn't feel right in the sets I was taking," Kalil said. "It was just about tweaking certain things and putting your feet in certain positions. It's little things, not changing my overall game, but the little things make the big difference. That's what those guys key in on."

The experimentation stretched into this week, when quarterback Matt Cassel will count on Kalil to protect his blind side against Quinn. Kalil said he's kicking back farther in his first step rather than stepping sideways, a problem he felt was a mental roadblock recovering from knee surgery that he hurdled recently. It allows him to beat pass rushers to the point of contact. That's critical against a speed rusher like Quinn, who has improved dramatically since the last time the two met in 2012 during Kalil's rookie season.

"He's had his two best practices this week," head coach Mike Zimmer said. "He's been very focused. He's very in-tune to what he has to get done. Yesterday was his best practice, and he looked good to me today based on the little I saw.

"Much, much better than earlier … according to Pro Football Focus," Zimmer joked.

While the popular evaluation site has been harsh on Kalil's performance last year and during the preseason, as Zimmer acknowledged tongue-in-cheek, Kalil said he's ready to face one of the game's best defensive ends.

"Luckily, it's happening now where I'm feeling comfortable rather than not feeling comfortable playing against Quinn," Kalil said.