"I think it's very unlikely that we would trade [the pick]," McDonough said.
McDonough said it's possible the team could be open to a deal if it's for an "established young star."
The Suns won the lottery Tuesday after finishing the regular season with an NBA-worst 21-61 record.
"Obviously getting the top pick in this draft with all the talent and all the different options, boy, I'm getting emotional," McDonough told reporters. "It was special. It was cool."
The Suns will likely choose between big man Deandre Ayton and Euro guard Luka Doncic. Ayton, who starred at Arizona, should be considered the favorite for the pick at this point. The big man is a natural replacement for impending free agent Alex Len, and neither Marquese Chriss nor Dragan Bender has emerged as a star in their first two seasons.
Doncic is a potential fit because of the Suns' desperate need for a long-term point guard after trading Eric Bledsoe and the hire of coach Igor Kokoskov. The former Utah Jazz assistant is the first Euro-born NBA coach and has a ton of experience developing young guards.