Complex sentence: Portsmouth Today, 7 February 2007 making his debut as a substitute in the Pilgrims' 4--0 home win against Coventry City on 11 April; however, he was unsuccessful in securing a long-term contract, and was released.
Split into simpler sentences: Portsmouth Today, 7 February 2007 making his debut as a substitute in the Pilgrims' 4--0 home win against Coventry City, on 11 April. However, he was unsuccessful in securing a long-term contract, and was released.