Complex sentence: He became a prime example of a promising player who peaked early on in his career and went on to play in Non-league football with Corby Town, Gainsborough Trinity, Stamford and Boston United.
Split into simpler sentences: He became a prime example of a promising player who peaked early on in his career. He also went on to play in Non-league football with Corby Town, Gainsborough Trinity, Stamford and Boston United.