[5] Marshall made a total of seven appearances in the league for Leinster during the course of the season, with five of these coming as starts, as the province won their third Pro12 title.
He also played for Leinster A in the 2012–13 British and Irish Cup, but missed the final against Newcastle Falcons after being forced off 23 minutes into the semi-final against Munster A.
[9] In the 2014–15 Pro12, Marshall played his highest number of league games for Leinster, making a total of nine appearances, all but two of these coming as a replacement.
[6] On 19 April 2015 Marshall made his European debut for Leinster, coming off the bench against Toulon in the 2014–15 Rugby Champions Cup semi-final.
[11] Marshall made his debut for the team on the opening day of the season, coming off the bench against Newport Gwent Dragons.
[5] Marshall played for Ireland in the Under 20s Six Nations and was part of the Under-20 team's squad for the 2010 Junior World Championship in Argentina.