DETROIT -- You didn’t have to be in Green Bay to see the problem. It’s so obvious to everyone. You don’t have to be an NFL player, a coach or even a general manager to see why the Lions have been horrendous for the past nine seasons.

Their defense is horrible and has been for a long time.

Yet, it hasn’t been fixed. No matter who the Lions bring in -- new players, a new defensive coordinator -- the results are always the same. The Lions’ defense can’t stop anyone, not on the ground and especially not in the air.

New coach Jim Schwartz is considered a defensive coach. It certainly doesn’t look like it. His team has been downright embarrassing on that side of the ball. The Lions’ 26-0 loss to the Packers in Green Bay on Sunday didn’t tell the whole story. The Packers could have easily scored 50 points on the Lions had it not been for all their penalties.

It was enough to make any fan throw their hands up and say enough already. Sure, it would have helped if the Lions weren’t shorthanded on defense. But it’s the NFL. There are always injuries. It’s not a good enough excuse. And yes, it would have been nice to have rookie, franchise quarterback Matthew Stafford and all-world receiver Calvin Johnson both playing against the Packers. It couldn’t have hurt.

They might have kept the score respectable, but ensure a victory? No way, no how. The only thing worse than the Lions defense is the news on Stafford’s injured knee. For sure, it should make Lions fans nervous.

ESPN reported Sunday that Stafford’s injured knee underwent a new MRI that will be examined Monday by Dr. James Andrews, according to sources.

Sources say the biggest concern is that Stafford’s knee cap is loose enough to require surgery, which could jeopardize the rest of his season. The Lions, of course, hope more rest -- the Lions have a bye this Sunday -- will provide Stafford with the necessary healing. Still, even with Stafford and Johnson in place, the Lions won’t win until they can stop the opposition. It’s sickening. Week after week, the defense, especially the secondary, is shredded.

The Lions have to get better on defense. And changes have to be made to stop this sinking ship. It just can’t go on anymore. The Lions are allowing 31 points a game. They’ve allowed 45 or more twice in six games. And they’ve allowed 26 or more in every game except in their lone victory, a 19-14 win over the hapless Washington Redskins.

"You can’t sugarcoat it,’’ Schwartz told the media after the debacle at Lambeau Field. "You’ll have a hard time finding the silver lining in this one.’’

Sadly, we have heard this one way too many times in Schwartz. Talking about how bad it is isn’t enough. You can’t stay the course. A solution must be found immediately – even if it means changing a scheme or cutting players ASAP.

There’s something wrong with the type of players the Lions are bringing in on defense. There just aren’t any playmakers, difference-makers. Who is leading the defense? The answer is no one.

The homer Lions fans and soft media members will laud the pass rush and their four sacks against Aaron Rodgers. Nice, but in reality, it didn’t affect the game. Rodgers still almost threw for 400 yards. It seems to happen way too much. Good quarterbacks eat up the Lions’ secondary with big plays all over the field.

That’s why it’s not unfair for fans to be mad at the Lions’ front office for hiring a defensive coordinator as head coach and then taking two offensive, skilled players with their first two picks in the first round. It’s indefensible.