Jeremy Lin's Teammate Airballs Birthday Cake Celebration, Hilarious Moment

Imagine having a wide-open layup ... and missing it.

That's the equivalent of what Jeremy Lin's Beijing Ducks teammate did on Chang Lin's big day this week ... winding up from point-blank range to beam the player with a birthday cake -- and he hilariously airballed it!!

The ex-NBA player shared it all on his Instagram this week ... showing the teammate getting the golden opportunity to throw a cake in Chang's face -- as part of a "tradition."

But the teammate completely missed the target ... and threw the dessert right into the window behind!!

Lin -- who rejoined the Beijing Ducks this past June -- roasted the player's hiccup ... saying, "My teammate w the biggest airball of the season lollll."

All in all, everybody was a good sport about it -- the team shared laughs after making sure to let one of their own have it ... joking and smiling as they point at the cake remains on the window.

Here's hoping the dude won't miss this badly on the basketball court anytime soon.