Born in Aberdare, Lucas began his football career when he joined Cwmaman and joined Swansea City at the age of 8. Having making progress turned professional for the 2010–11 season. Between 2010 and 2011, Lucas signed a contract, keeping him until 2013 and was awarded the club's youth development player of the season award at the end of the 2009–10 season. He made his senior debut for Swansea on 7 May 2011, in a 4–0 victory over Sheffield United. After being told he will be loaned out to gain first team experience, Lucas joined Burton Albion on loan on 26 January 2012, until the end of the season. Lucas made his Burton Albion debut three days later, making his first start, in a 1–1 draw against Oxford United. However, this turns out to be his only Burton Albion appearance, as he struggled with a hamstring injury that saw him missed seven matches. Lucas regained his fitness, only to sustained a fractured back that ruled him out for the entire season. Following his loan spell at Burton Albion came to an end, Lucas signed a new three-year contract with Swansea in June 2012. On 30 January 2014, Lucas signed for Cheltenham Town on an initial one-month loan deal. Lucas made his Cheltenham debut two days later, in a 1–1 draw against Northampton Town. Lucas made his second and last appearance seven days later on 8 February 2014, in a 0–0 draw against York City. After making two appearance for the club, Lucas returned to his parent club on 28 February 2014. Lucas missed the first seven months of the 2014–15 season through injury. Lucas then suffered a further injury on his playing return for Swansea City Under-21s. In July 2015 Lucas signed a one-year contract extension with Swansea. After nineteen on the sideline, Lucas made his return in the club's reserve, where he played the second half of Swansea Under-21s 2–0 defeat to Aston Villa on 22 February 2016. After the match, Lucas stated the win over Aston Villa was his personal victory. Lucas was released in May 2016, ending his fifteen years association with the club.
Lucas signed a short-term contract with Scottish club Motherwell in July 2016. He played in a Scottish League Cup tie against Annan Athletic, but was forced off due to injury. On 31 August 2016, Lucas was released from his contract, but then on 14 September 2016, he signed a contract with the club until January 2017. On 10 January 2017, he extended his contract until the end of the 2016–17 season. He was released by Motherwell at the end of the 2016–17 season.
