Dunney made way for Portsmouth's Andy O'Brien at the break.
Elsewhere, David James conceded four second-half goals against Denmark as England suffered their biggest defeat in 25 years.
James replaced Paul Robinson at half-time and although he was at fault for the first goal, there was little he could do to prevent the remaining three.
United's Wayne Rooney netted a late goal for England in a 4-1 defeat in Copenhagen, where former City full-back Niclas Jensen starred for the hosts.
Former City keeper Kevin Stuhr Ellegaard, now at German side Hertha Berlin, featured for the Under-21s the previous evening as a late Darren Ambrose goal gave England a 1-0 win.