[3] McNulty completed a Business degree at the Waterford Institute of Technology between and joined the senior hurling team in his second year.
[4] McNulty joined the De La Salle club at a young age and played in all grades at juvenile and underage levels.
On 15 December 2013, he lined out at full-back when De La Salle faced St. Carthage's in the Waterford Under-21 Championship final.
McNulty assumed the captaincy of the De La Salle under-21 team in 2015, however, the championship was delayed for almost a year for a number of reasons.
On 14 October, he came on as a 34th-minute substitute and scored 0-02 from play when De La Salle defeated Dungarvan by 1-21 to 0-12 to claim the Waterford Senior Championship.
[7] McNulty subsequently broke onto the starting fifteen and was selected at midfield when Waterford faced Clare in the Munster final on 10 July.
He played his last game in the minor grade on 29 June when Waterford suffered a 2-25 to 0-12 defeat by Tipperary at the Munster semi-final stage.
[13] On 12 July 2015, McNulty was an unused substitute when Waterford were beaten for the fourth time in six seasons by Tipperary in the Munster final.