Jedi from the past

Y/n is a Jedi padawan of the old republic who fought in the war against the sith empire. This was until one day while fighting against enemy forces, his ship gets trapped in a freezing nebula, which makes him stay undercover and hidden until he is found. Go beyond and explore the past before the phantom menace movie. How would this affect the main story of Star Wars?

I don't own any rights of Star Wars, it all belongs to its creator Lucas films.