It’s been a tough offseason for the San Francisco 49ers.

For starters, Alex Smith is their quarterback. But it gets worse.

Last week, they cut top corner Nate Clements, apparently in an effort to free up space for Nnamdi Asomugha. Asomugha signed elsewhere, as did Clements, and now the Niners are left with Shawntae Spencer and Tramaine Brock at that position.

Uh huh. Shawntae Spencer and Tramaine Brock.

Also gone are starting linebackers Takeo Spikes and Manny Lawson.

And now they’ve lost another defender, as monster nose tackle Aubrayo Franklin has signed a one-year deal with the New Orleans Saints, according to ESPN’s Adam Schefter. Franklin could make a big impact in the Bayou, where he’ll join Sedrick Ellis and Shaun Rogers up the middle and immediately upgrade a so-so run defense.

In San Francisco, a middle-of-the-pack defense has lost four starters in less than a week.

What’s baffling is that the Niners reportedly have over $30 million in cap space. There’s no way they can say with a straight face that they’ve gotten better this summer, so they’re clearly thinking hard about 2012 and beyond. Not to be a conspiracy theorist, but don’t forget that new head coach Jim Harbaugh coached shoe-in 2012 No. 1 overall pick Andrew Luck at Stanford. They also might not mind having some extra cash to help build a stadium that the state of California refuses to pay for.

Depressing stuff.

And did I mention that Alex Smith is their quarterback?