The 30-year-old striker has signed a two-year contract with the option of a third.
Dani joined Espanyol in July 2004 after ending his contract with Barcelona following a brief loan spell at Real Zaragoza.
He scored five goals for Espanyol last season but faded out of the reckoning at the tail-end of the campaign and said he was affected by the negative atmosphere amongst the players at the club.
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The striker, who began his career at Real Madrid, made his name when he scored 12 league goals for Real Mallorca in the 1998-99 season.
He won the first of five international caps in November 1998 and secured a $15.5 million move to Barcelona at the end of the season.
Despite scoring 11 goals in 27 games in his first season at the Nou Camp, he was then virtually ignored by successive coaches, playing just 23 league games from 2000-2001 before leaving the club by mutual consent after almost three years on the sidelines.
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