You know it's been a long NFL season when your long snapper fractures something called the "sacrum," a large triangular bone at the base of his spine.

"I guess it's kind of the old saying, 'When it rains, it pours,' " said the Vikings' Cullen Loeffler, who also dealt with a rotator cuff injury two weeks ago. "For whatever reason, it seems I've been on the losing end of things lately."

Vikings coach Leslie Frazier called it a significant injury requiring a minimum of two weeks and up to six weeks of recovery time. With only five weeks left in the season, Loeffler could end up on injured reserve as early as this week. His streak of consecutive regular-season games played will end at 123, 21 short of Mike Morris' team record for a long snapper.

Frazier said Monday that the Vikings will work out long snappers and sign one this week. Defensive end Jared Allen made four snaps on punts and two on PATs without any problems, but he's only the emergency long snapper.

At least one of Loeffler's teammates is irate with Falcons special teamer Kerry Meier for delivering the hit that likely ended Loeffler's season during Sunday's 24-14 loss in Atlanta.

Chris Kluwe, the team's punter and holder, wrote via Twitter, "To the Falcon that cheap-shotted Loeffler -- I hope someone does the same ... to you and knocks you out for the rest of the year too."

Meier landed a legal block to Loeffler's chest. Loeffler was outside the right hash marks when he turned left to pursue returner Eric Weems, who was outside the left hash marks -- about 10 yards away -- and moving quickly past Loeffler. Loeffler wasn't going to make the tackle, but he wasn't entirely out of the play either.

"It seemed to have been a legal hit," Loeffler said. "Now, I wasn't that close to the returner. ... That's part of the game. That's what happens in returns like that. Unfortunately, you're vulnerable."

Injuries, injuriesAnother player who could be heading to injured reserve is safety Tyrell Johnson. Frazier said Johnson suffered a "significant" hamstring injury that probably will sideline him for "a while."

Johnson started in place of Husain Abdullah (concussion) for the second consecutive week but was injured early in the second quarter. He was replaced by rookie Mistral Raymond, who could make his NFL starting debut Sunday if Abdullah is held out another week.

Cornerback Asher Allen, who left Sunday's game late in the first quarter, has a sprained AC joint in his left shoulder. Frazier said Allen will be "day-to-day" and his status will depend a lot on how much pain he can tolerate.

Receiver Michael Jenkins also came out of the game because of a knee injury that Frazier said could "cause him to miss some time." The Vikings expect to know more about Jenkins' status Wednesday.

And, finally, running back Adrian Peterson, who missed the game because of a high left ankle sprain, has a chance to play this week, according to Frazier.

"He is improving," Frazier said. "So that is encouraging for us."

Bad executionFrazier dismissed reports of Falcons players saying they knew which play the Vikings would run on fourth-and-goal from the 1 late in the game. Linebacker Sean Weatherspoon knifed in off the left side of the line and dropped Toby Gerhart for a 2-yard loss.

"I don't have a problem with the play. I have a problem with the execution of the play," Frazier said. "If we block it the way it's supposed to be blocked, it's a touchdown. Whether they knew it or not, we didn't block the play.

"There are a lot of plays that we run in our offense that people are going to know that Adrian Peterson is going to get the football in this situation, they've still got to stop the play. That's not unusual. They've still got to stop the play."

It was right guard Joe Berger's responsibility to pull and kick out the outside defender on that play. Berger pulled, but blocked the wrong guy when he turned upfield early.

Etc.• As of Monday morning, the Vikings had fewer than 3,000 tickets remaining for Sunday's game against the Broncos. They have until noon Thursday to sell out and avoid their first home television blackout since the end of the 1997 season.

• The Vikings added tight end Mickey Shuler to the practice squad, according to his agent. Shuler was a seventh-round choice in 2010 who was claimed by Miami after the Vikings waived him early in the season. He played for the Dolphins last season, but was waived this year and claimed by Cincinnati, where he failed a physical in September.