In Cell's original timeline, an alternate Future Trunks went into the past and helped Goku just as in the main timeline. Future Trunks and the Z Fighters manage to defeat the Androids and he travels back to his alternate future timeline. Since this was a completely different timeline, the events of Cell never occurred and he did not expect to encounter Cell (and may not have even been aware of Cell's existence). When he returned to Age 788 of his alternate future timeline, he disabled the other
Future Vegeta Dragon Ball+BreezeWiki
Future Trunks Briefs(Cell's Timeline), Animated Character Database
Trunks Briefs, Animated Character Database
Saibamen, Animated Character Database
Tights, Animated Character Database
Dragon Ball Z: History of Trunks [Import] : : Movies & TV
Future Trunks, Dragon Ball Wiki
Gotenks, Animated Character Database
Category:Starseeds, Animated Character Database
Category:Saiyan, Animated Character Database