Thanks again, obvious headline. You’re really on a roll today.

Greg Jennings has been an important and vital piece of the Green Bay offense for quite some time now. He leads the Packers in receiving yards this year, a position he’s held since 2007. He has 21 touchdown receptions over the past two years, a stretch in which he’s also had at least 70 receiving yards per game, and nearly 80 in 2010. He’s pretty good.

Yesterday Jennings missed his first game in three years, giving us the opportunity to measure just how much he means to Aaron Rodgers et al. Rodgers had his worst game of the season, with Kansas City holding him to just 17 completions on 35 pass attempts, and 235 passing yards and a touchdown.

Sunday was a glimpse into life without Jennings, and only a glimpse. A one-game sample size certainly can’t forecast what’s ahead for Green Bay during the final two games, or what the Packer offense would look like if the 28-year-old were to suffer another serious injury in the future.

But it was still a pretty ugly glimpse.

The Packers persevered through a mountain of injuries last year on both sides of the ball on their way to becoming champions. Ryan Grant and Jermichael Finley were lost early in the season, and linebacker Nick Barnett soon followed. Rodgers even missed a game with a concussion, and Charles Woodson broke his collarbone in the Super Bowl.

It was a never-ending parade of bandages and bruises, but the one constant was the wide receivers. Donald Driver was hobbled, but 36-year-old football players are often hobbled, and he still only missed one game. Going down the depth chart, Drivers’ one-game absence was the only game missed by a Packers wideout, which includes full seasons from Jennings, James Jones, and Jordy Nelson.

Even without Eric Berry, the Chiefs have a strong secondary that’s led by the emerging Brandon Flowers, and they’re allowing just 209.6 passing yards per game. But KC is also allowing 7.7 yards per pass attempt, an inviting number that’s only slightly lower than the Colts’ 7.9, and Indy’s secondary is ranked 24th.

Strong secondaries haven’t held back the Packers often this year, and Sunday that resilience ended. Rodgers has thrown against three other top 15 secondaries (Lions, Chargers, Rams). Against a Lions unit that’s giving up only nine yards more per game than Kansas City, he finished with 307 yards and 9.3 yards per attempt, and the latter number dropped to 6.7 against the Chiefs.

Overall in those games Rodgers averaged 290 yards and three touchdowns, with a completion percentage of 69.7. His accuracy dropped to 48.6 yesterday, setting a season low, and it was second-lowest percentage during Rodgers’ four years as the starter in Green Bay.

The Chiefs deserve credit, and the widespread injuries on the Packers’ offensive line were definitely a factor too. But there was something missing, and the only major variable gone for the Packers’ passing arsenal was Jennings, the Pro Bowl receiver who was healthy and thriving for the other 13 games that ended in wins.

Jermichael Finley raised his game, eclipsing the 80-yard barrier for just the third time this year, but shutting down speedsters like Nelson and rookie Randall Cobb on the outside became easier without Jennings to attract attention. The longest reception by a Green Bay wide receiver yesterday was just 22 yards, which was the shortest deep ball by the group this season. A Green Bay wide receiver has caught a 60-plus yard reception seven times this year, with 54.7 yards the length of the average long ball per game.

Jennings will be back for the playoffs, with Mike McCarthy saying last week that he’ll need 2-3 weeks to recover from his knee sprain. At first the seemingly safe assumption was that Rodgers’ penchant for pass distribution would easily compensate for the loss, but the early returns show that Green Bay is lacking nearly 30 yards worth of deep balls, both from Jennings himself, and through his role as a defensive distraction.