Lindsey Vonn -- 'Just Friends' with 'Vikings' Star ... But I'm Open Minded!

Some bad news, good news ...

The bad news -- Lindsey Vonn says she's "just friends" with "Vikings" star Alexander Ludwig.

The good news -- she's "open-minded" about letting him out of the friend zone.

31-year-old Lindsey and 23-year-old Ludwig got people talking last week when they left Craig's in L.A. together lookin' pretty damn couply after a fancy dinner together.

But Vonn says there's no official relationship ... yet ... saying she barely knows the guy.

Here, Lindsey ... maybe this pic will help change your mind.