Oh, no [VIDEO]

Dalvin Cook was reaching for his knee before he even hit the ground.

Dalvin Cook was reaching for his knee before he even hit the ground.

What is it with these Minnesota Vikings and their knees? 

Last season Teddy Bridgewater missed the entire season after blowing his knee out, and Adrian Peterson went down in Week 2. 

This year, after an excellent Week 1, quarterback Sam Bradford has missed three straight games after suffering an injury to a knee which he's had operated on twice. His replacement Case Keenum played poorly in a loss to the Steelers, then rebounded with a great game last week over Tampa Bay. 

In going 2-1, the Vikings offense has heavily featured rookie running back Dalvin Cook, who entered the fourth game ranked second in rushing yards (288, on 61 carries, 1 touchdown) in the NFL. Facing the Detroit Lions at home, Cook was well on his way to another fine game: 66 yards and a score, plus a fun endzone dance --

-- midway through the third quarter) when... well...

Look away if you have low tolerance for second-hand knee pain, or if the Vikings' cruel luck with injuries tends to turn your stomach.

Note how Cook is grabbing for his knee from the moment he plants his left foot. Also, note that he fumbled the ball. Detroit recovered the ball near midfield, and proceeded to march downfield for the go-ahead touchdown; the Lions lead 14-7 at the start of the fourth quarter.

Cook left the game immediately after that play and was helped from the field. The Vikings announced that Cook will not return during this game. 

Uh, go Twins?