Complex sentence: In September 2007, he joined Carlisle United on a months long loan, he scored his first senior goal whilst at "The Cumbrians" in a 3-1 victory at Bournemouth.
Split into simpler sentences: In September 2007, he joined Carlisle United on a month-long loan. He scored his first senior goal whilst with the Cumbrians in a 3--1 victory at Bournemouth.