EDEN PRAIRIE, Minn. -- The routine started at the beginning of training camp: Matt Kalil would step onto the field a half-hour before the start of practice, hoping to find through drills what came so easily to him as a rookie. Ten minutes before practice, offensive line coach Jeff Davidson would join him, and the two would reconvene for another 10 minutes after practice, with Davidson mimicking a pass-rusher and Kalil testing out different approaches to stopping him.

The steps came so easily as a rookie, when Kalil went to the Vikings with the fourth overall pick, stalemated a string of established pass-rushers late in the season, and played in the Pro Bowl three weeks after appearing in his first playoff game. But by his own admission, Kalil struggled in his second season, playing through a knee injury during the last two months of the season that changed his approach to pass blocking as he tried to compensate for the pain.

Matt Kalil spent training camp trying to find the form of his Pro Bowl rookie season of 2012. Jim Mone/Associated Press

"I think the biggest problem I had was kicking sideways, rather than kicking back, because I didn't trust my knee to get me back there," Kalil said. "I'm doing it now, and my knee's fine. It's just a mental block. It takes awhile. It's not going to be overnight when your knee was messed up all last year."

Kalil says he's ready to go now, that his experimentation with different techniques in the preseason -- which resulted in some unsightly exhibition games -- helped him make up for the time he lost after knee surgery and learn to trust himself again. As Kalil heads into his third year, the Vikings need to know they can count on him.

He'll begin the season facing Rams All-Pro defensive end Robert Quinn and the rest of a defense that put more pressure on the quarterback than almost any other team in the league. According to ESPN Stats & Information, the Rams disrupted 20.5 percent of opposing quarterbacks' dropbacks last season, which was the highest rate in the NFC and the second-highest in the league behind the Buffalo Bills. The team drafted defensive tackle Aaron Donald in the first round this year, giving the Rams four former first-round picks in their defensive line rotation.

"I would say this: We aren't spending any time being bored [preparing for the Rams]," Davidson said Thursday. "We spent about an hour this morning talking through multiple looks, and the way we're treating all the different pressure they bring. You have to understand what your rules are in protections, because they're going to give us some things we have not seen, and we have to react to it."

For the Vikings, Sunday won't just be about Kalil handling Quinn. The Rams have too many other pass-rushing threats -- and can bring extra pressure from too many other places -- for that. But there's a reason the Vikings spent plenty of time putting Kalil on an island during the preseason: They need to know that more often than not, him handling his man will be the least of their worries.

"Realistically, any left tackle in this league is going to be asked to match up well against any opponent," Davidson said. "He's always going to have a decent rusher that we're going to see on Sundays. Each guy presents a different challenge."

It's why Kalil has put in the extra work in recent months, to make up for time he lost in the Vikings' offseason program following knee surgery, and to diversify his repertoire after the league figured out some ways around him last season. The path to Kalil being a franchise left tackle is still out there. He's trying to make sure he puts in the work to stay on it.

"I think the goal is to come out, have a great first game, build that confidence on the season and start from there," Kalil said. "I know what I have to do to be a great player."