Complex sentence: At the end of the 1984 season, the NASL collapsed leading DuBose back to the Tampa Bay Rowdies which now operated as an independent club playing exhibition games and invitational tournaments.
Split into simpler sentences: At the end of the 1984 season, both the NASL collapsed. This led to a return to the Tampa Bay Rowdies which now operated as an independent club playing exhibition games and invitational tournaments.