The 21-year-old, who netted eight times last term, scored in the 2-0 win against League One side Brighton and Hove Albion in the Carling Cup.
McKay told BBC Radio Northampton: "When the fans notice what you're doing out there, it's a confidence boost.
"If I can double what I got last year, that'd be a good season. Hopefully, this will kick-start the season."
Source: BBC Sport
Source: BBC Sport