Career
He joined the Colchester United academy in 2012 for his scholarship, and made his professional debut for the club in January 2015. He is also a graduate from the Chelmsford-based P.A.S.S. Academy. After playing Sunday League football for Ongar Juniors and spending time with Maldon Town, Lapslie joined Colchester United at the age of 16, before signing a professional development contract with the club one year into his two-year scholarship alongside Michael O"Donoghue in April 2013.
Then-academy manager Tony Humes described Lapslie as a "dynamic central midfielder" who is a "leader in the team".
During the 2013-2015 season, Lapslie featured regularly in the successful under-18 side, helping his team to a Youth Alliance South East league title and Youth Alliance Cup double, starting in the 4–2 final victory over Bradford City at Valley Parade on 29 April 2014. Lapslie first travelled with the Colchester United first-team squad in December 2012, travelling to Bournemouth for their League One fixture, and travelled again in the 2014-2015 season for a trip to Crewe Alexandra in September 2014, having been in good form for the under-21 development squad.
2014-2015 season
He then made his full debut and home debut on 24 January, starting and playing the full 90 minutes in Colchester"s 2–0 relegation battle victory over Leyton Orient. Lapslie was thrust into the first-team for successive league matches, admitting that "I can"t believe it at the moment, I have to keep pinching myself.. being involved with the first team".
He notched his tenth league start on 11 April in Colchester"s 1–0 defeat by Coventry City, announcing that he "couldn"t have imagined playing so many games, before this season started".
He made his final appearance of the season on 14 April as the U"s were defeated 6–0 by Chesterfield, bringing his appearance total to twelve in all competitions. He was then offered a three-year contract to extend his stay with the club until the summer of 2018, which he signed on 23 April. 2015-2016 season
Lapslie made his first appearance of the 2015-2016 season on 17 October 2015 when he replaced Joe Edwards in the second-half of a 5–0 thrashing by Wigan Athletic at the DW Stadium.