Helder has stepped in for Fredi Kanoute - on African Nations Cup duty with Mali - in the games against Liverpool and Sunday's FA Cup tie at Manchester City, scoring against the Reds a fortnight ago.
"I was delighted with the way Postiga dovetailed with Keane," said acting boss David after the 1-1 draw at the City of Manchester Stadium.
"In the second period they played well together and it was a combination worth seeing.
"The fact that Dalmat is in a wide position attracts that little more attention so there is more space to play into the front players.
"I thought they were very good. They worked very hard and looked a partnership, looked as if they could play together."
David Pleat has expressed his satisfaction with the growing understanding between strikers Robbie Keane and Helder Postiga.