Complex sentence: On 19 August 2011, Arsenal confirmed that they had signed Campbell, but it was revealed on 27 August 2011 that he had failed to obtain a work permit to enable him to play in England.
Split into simpler sentences: On 19 August 2011, Arsenal confirmed that they had signed Campbell. It was revealed on 27 August 2011 that he had failed to obtain a work permit to enable him to play in England.