During the second quarter of Sunday's 20-16 win over the Detroit Lions, Allen was about 10 yards away from quarterback Daunte Culpepper, who had rolled out toward the right sideline on a bootleg and was just releasing the ball. Cherilus, who was on his knees at the line of scrimmage, dove backwards, putting his helmet in front of Allen's left knee and his right shoulder pad directly into the outside of the knee.
After a couple of seconds lying on the turf in pain, Allen got to his feet and limped past trainer Eric Sugarman towards Cherilus. Allen had to be restrained by Ray Edwards and Sugarman before being helped off the field by the medical staff.
"Lucky for me, I was already on some good pain-killers for the shoulder (sprain)," Allen said.
"I know the league will be reviewing that because they have a process they go through," Vikings coach Brad Childress said. "I don't think you can get yourself perpendicular to the goal line and block that direction. I think that's what came up a few years ago with the Denver Broncos-Cincinnati game. Somebody went low on somebody, and I think that brought that rule forward. That's kind of the way I saw it."
A quick search through the 100-plus pages of playing rules came up empty when looking for a reference to blocking perpendicular to the goal line, and an NFL spokesman would only say in an e-mail that the league would have more information "about this play" on Friday, the day when fines are normally handed down.
Safety Darren Sharper on Monday left little doubt how he felt about the block by Cherilus.
"Oh, that was a cheap shot, man. That's one of those things that goes against the code of ethics between football players in which you don't take a shot at a guy that's vulnerable," Sharper said. "You could ruin his career. And how his knee bent, that was nasty. You just don't do that. You don't do that at all."
Asked if knees are sacred in football, Sharper said, "Right. You get a guy in a vulnerable position and you don't want to necessarily try to lead with your head, take a guy out. Or a quarterback that's in a vulnerable position, you're running straight at him and then all of a sudden you duck down and try to take a knee out. That's uncalled for."
Cherilus wasn't flagged for a penalty on that play. On the next play, linebacker Napoleon Harris and fullback Moran Norris got into a scuffle away from the play. Both players were flagged for personal fouls and Norris was ejected for throwing a punch.
Allen returned to the game in the second half and registered two sacks of Daunte Culpepper, but his status this week is uncertain. Early indications were that there was some concern the medial collateral ligament may have been sprained, according to Jay Glazer of FoxSports.com, but the Vikings typically keep injury information close to the vest.
No matter the severity of the injury, Sharper maintained that there was no need for that type of block in that situation.
"From what I saw in the shot he took, I mean really he didn't necessarily need to do that," he said. "You could've got your body in front of him. It's like he didn't even want to get his body in front of him. He just said, 'I'm going to go ahead and take a shot at a guy's knees and cut him.' He could've kind of blocked him up high, but he cut him low."
Childress said Allen was in the training room early Monday morning. The defensive end's history has been to play through pain.
Allen played the week after he suffered a shoulder injury earlier this year, one that he said was a Grade 3 sprain of the AC joint that usually keeps players out for at least a few weeks.
"I have a rule: I'm going to have to be dead before you cart me off that field," Allen told KFAN, calling the hit unnecessary. "Then I got up and I was so mad that I figured if my season is over, that dude's season is over as well – I'm taking him with me."
"He's an exhibitionist. He likes that kind of stuff. He don't mind that. He thinks it might help him out with the chicks, I guess," Sharper said.