Lamar Odom -- I'M OFF TO SPAIN ... And I'm Taking My Wedding Ring!

Lamar Odom doesn't just think he can save his basketball career in Spain ... he also thinks he can save his marriage ... and to prove it, he rocked his wedding ring on his way out of the country.

Odom was all smiles as he rolled through LAX on Tuesday ... right before he boarded his plane to Espana, where he'll join a Spanish pro basketball team (Laboral Kutxa Vitoria).

But it was clear he wanted to make a statement about the state of his marriage to Khloe Kardashian -- by wearing the ring on his finger.

As we previously reported, Khloe already filed for divorce ... and wants out of the marriage.

Clearly, Odom is an optimist these days.