The flanker, who has previously represented New Zealand at under-20's level, arrived at BT Murrayfield last month from Otago and has yet to turn out for Alan Solomons' men.
Blake qualifies to play for Scotland through his grandparents and Dodson is adamant the youngster will bring unique qualities to the squad.
"I don't think it is sending the wrong message out to our youngsters. It might have done had we not capped so many young Scottish players over the last two years," he said.
"Hamish Watson is in the squad, so is Sam Hidalgo-Clyne and Ben Toolis. It is not as if we've brought Hugh Blake in and no-one else is getting capped.
"People should also not make the assumption that we have not been tracking Hugh Blake. We've been tracking him for ages.
"We had him watched down in New Zealand making sure the progress is there and Vern believes this boy can bring something to the squad that we don't have. He has a special skill set that we don't possess."
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