Complex sentence: In 2004, after a big decline in attendance in recent years, the Cangrejeros were sold to MLB-player José Valentín who decided to moved the team to Manatí, with the approval of the mayor of San Juan, causing controversy among fans of the Cangrejeros.
Split into simpler sentences: In 2004, after a big decline in attendance in recent years, the Cangrejeros were sold to MLB-player José Valentín. Valentin moved the team to Manatí, with the approval of the mayor of San Juan causing controversy among fans of the Cangrejeros.