Vikings quarterback Tarvaris Jackson appeared to aggravate his injured left knee on Friday night. "I was fine. I guess I just wasn't ready for that right now," Jackson told ESPN after the practice. "But it's fine. It's not bothering me still. It was awkward for me. I think it was just some scar tissue." He sprained the MCL in his left knee last weekend. "I just felt something pop for a quick second," Jackson said. "But after I walked to the sideline it was pretty much OK. It's fine."