Vikings left tackle Matt Kalil is fine with being under the microscope, but he's not about to let a football stats-based website bring him down.

On Thursday, Kalil spoke with reporters about the way ProFootballFocus.com has rated his play this season. According to the Pioneer Press, the site ranks Kalil as the third-worst left tackle in the NFL this season. Kalil's response:

“You can’t listen to some people who don’t know what they’re talking about, who want to go on Pro Football Focus, the website who they hire random fans and give them a training camp on how to grade people,’’ Kalil said. “And people want to live on that site when it’s not really a credible site.

“I’m not going against them because they hammer me. But I mean, it’s not a credible site. They don’t know the blocking schemes, they don’t know who’s fault (a mistake might be).’’

As John Holler from Viking Update put it, Kalil and Pro Football Focus have become mortal enemies.

Kalil's struggles, in part, could be the cause of a knee injury that he's played through all season. But he's not using that as an excuse.

“I’m playing with a chip on my shoulder now and into next year,” Kalil told Holler. “In the grand scheme of things, I’ve definitely got something to prove – not so much to anyone else, but to myself. I’ve never really been injured, so this is a new thing for me. If anything, this year has made me more manly tough than I’ve ever been.”

Kalil could use some extra help chip-blocking on Sunday when he's assigned the task of stopping Lions defensive end Ziggy Ansah, who torched Kalil for 2 1/2 sacks in the first meeting this season between Minnesota and Detroit. One NFL.com writer said Ansah made Kalil look like an "18th century stone gargoyle."

The Vikings and Lions play in Detroit at 3:25 p.m. Sunday.