After playing several games for the academy at Coopers Technology College in Chislehurst, Porter was promoted to the first team, making his debut in the FA Cup.

[9] At the end of the season, Porter returned to Orient and scored a hat-trick for the O's in a 5–0 demolition of Finnish second division side SJK during their pre-season tour of Finland.

[11] A string of impressive performances, including a goal in his FA Cup début against Bromley, soon saw him attract interest from the likes of Nottingham Forest and Ipswich Town.

He signed on a youth loan for Colchester United on 1 January 2013 until the end of the season[15] and made his début the same day, coming on after 73 minutes as a sub in the 3–0 defeat at Crawley.

[17] Porter made his first appearance for "The Dons" two days later in a pre-season friendly game against Conference South side Sutton United at Gander Green Lane that resulted in a 4–0 win.

[18] On 24 January 2014, Porter returned to Burnley early from his loan after falling out of favour at Wimbledon, amid rumours of a training ground bust up with manager Neal Ardley.

[22] Despite missing a considerable period through injury, Porter made 31 league appearances, scoring 6 goals, and was rewarded with a new one-year contract at the end of the season.

[29] Porter started the season brightly putting in eye-catching displays scoring in victories at Champion Hill against Hendon and his former club Cray Wanderers.