Merrick stressed he supported New Zealand Football but didn't feel it was fair that de Jong spent time in the commentary box.
"To me he's very much got a conflict of interest making comments on how our players perform and I'm a very loyal person to our players and extremely supportive of all our players, especially All Whites who have really been outstanding when they've gone and played [for New Zealand] in Japan [last month], came back fatigued and never missed a beat with the Phoenix.''
Whether it's a conflict of interest or not remains to be seen given de Jong doesn't influence All Whites selections in his role.
Nobody from New Zealand Football was available to comment on Merrick's concerns today despite repeated requests from the Herald, while a spokesperson from Sky TV didn't return calls.
Sky's lead football commentator Andrew Dewhurst said it wasn't a matter he could speak about.
"I'm just the other voice in the box,'' he said.
Merrick wanted to make it clear there was no bad blood between him and New Zealand Football.
"I've never officially had any contact ever from New Zealand Football but I do think they're a good organisation. They're on the right track, there's a new CEO and there's changes there and I think I will do everything I can to support New Zealand Football.''
The eighth-placed Phoenix play their penultimate game of the A-League season on the road against Sydney FC on Sunday.