Slane made his debut for Motherwell on 16 May 2009 in a league match away to Hamilton Academical. He was an 86th-minute sub during the 3–0 win. Slane played in Motherwell's Europa League matches against Llanelli and Flamurtariin the summer of 2009, scoring the third goal in the 8–1 second round second leg win over Flamurtari. Slane was a trainee at Motherwell, but refused to sign a contract. When he signed a contract with Celtic in February 2010, Slane was criticised by Motherwell chairman John Boyle for showing a lack of loyalty to the club.
Celtic
On 1 February 2010, Slane signed a four-year contract with Celtic. He made his reserve debut in a 4–1 win over Queen of the South's first team. Slane missed the entire 2010–11 season due to a cruciate ligament injury to his knee. On 31 January 2012, Slane signed with English League One club Milton Keynes Dons on loan until the end of the season. Slane made his SPL debut for Celtic on 18 August 2012, as a substitute against Ross County. He was loaned to Scottish First Division club Partick Thistle in October 2012. After discussions with Celtic manager Neil Lennon, Slane was released from his contract in January 2013. Lennon stated, "...he was doing really well but he got a bad injury in a bounce game and that set him back for a while. He had loans at MK Dons and Partick Thistle but it didn't quite work out for him. With his talent it should have gone well but it didn't. It came to January and I told him he could stay on with our development side but he's better than that level. He had the option to stay or go and he decided to go." Lennon also added that Slane "... still has a bit of growing to do. He has to find his niche in life and the game. I really hope he finds that."
Ayr United
On 25 September 2014, Slane signed for Ayr United, having played in the club's previous two fixtures as a trialist. Slane was released by Ayr on 2 February 2015.
Clyde
Having already played twice for the club as a trialist, Slane signed for Clyde on 27 February 2015.
Personal life
A couple of months after leaving Celtic with a £10,000 pay-off, Slane appeared in the Scottish tabloid press as a result of a four-day 'bender' in Amsterdam with friends. Compromising pictures of him appeared on Twitter which he initially claimed were faked but later admitted were real. Slane had initially intended to spend his pay-off from Celtic to fund a hip operation, but ended spending most of it on nights out and the trip to Amsterdam. He is also a keen supporter of Argentine side Boca Juniors.
