Complex sentence: He was key to the U.S. preparation for the 1994 FIFA World Cup, playing in 12 games, starting 7, before the tournament, but was left off the roster and retired from the national team that year.
Split into simpler sentences: He was key to the U.S. preparation for the 1994 FIFA World Cup, playing in 12 qualifying games and starting in 7. However, he was left off the roster for the tournament itself and retired from the national team later that year.