Jay Cutler Seen Chatting Up Hot Blonde in Miami Days Before Kristin Pic

Jay Cutler's cryptic photo with his ex, Kristin Cavallari, appears to have been a red herring after all ... because the dude was getting his flirt on with another hot blonde just a few days prior, and definitely looked single.

The former QB was spotted chatting up a mystery woman last Wednesday at the 1 Hotel in South Beach, where he was sitting poolside and talking to her for hours. BTW, this wasn't Kristin ... who posted that weird pic of the two of them just three days later.

Eyewitnesses tell us Jay was with his buddies up at the rooftop pool for a bit, only to go back inside ... and he emerged with this woman. They pulled up a couple of chairs and ordered more drinks -- clearly enjoying each other's company.

No signs of PDA ... but we're told Jay and the woman looked very friendly, in more than a "we're just pals" kind of way.

As for the hot blonde, she could be Madison LeCroy, with whom Jay recently had a fling.

Now, as for where this leaves things on the Cavallari front ... it's still a little unclear, but the photo this weekend at least proved the two are still close.

Kristin's caption read, "The world is full of users. 10 years. Can't break that" -- which is about as confusing a statement one could make on where things stand ... especially since they've already filed for divorce.