Complex sentence: In the summer of 2009, he was about to be transferred to Real Zaragoza, but the deal collapsed after the two parties could not reach an agreement; the move was finally cancelled on 29 July, and the player returned to Wolfsburg.
Split into simpler sentences: In the summer of 2009, he was about to be transferred to Real Zaragoza, but the transfer could not be completed because the two parties could not come to an agreement. The deal was finally canceled on 29 July, and the player returned to Wolfsburg.