Since both of these sentences are speaking of the same subject (the player), the way to combine them would be to use a conjunction. The best conjunction for this purpose is "and."
So the combined sentence would be:
The player jumps into the air and (she) has just scored the winning goal.
*** Note that I put the word "she" in parentheses because it's optional to include that word in the connected sentence. With or without the word "she," the sentence makes sense and is grammatically correct.
