Small Forward
This is the most complicated position to judge, in my opinion. The Suns have a potential scoring star in T.J. Warren starting at small forward, a young player still in his rookie contract who might be able to average 20 points and 7 rebounds per game this upcoming season if healthy.
The roster also boasts Dragan Bender, a position-less big man, who hypothetically could play small forward if the team needed in larger lineups. Throw in Derrick Jones Jr. (if he remains on the roster) and there really is a logjam of sorts of young talent at small forward at the moment.
All that being said, none of them either shoot the three with any above average ability, nor do they play enough defense to require that they receive guaranteed minutes. Certainly the Suns hope that Warren and Bender (if Bender plays the three) can grow enough this coming season to stake that claim to the position, but at the moment, the fact that so many people in the Valley of the Suns have been dreaming of a starting lineup that includes Josh Jackson and a roster that is T.J. Warren-less, then there obviously is enough of a deficiency at the position there to believe that there is room for improvement in the draft.
There are several players who appear to maybe be available for the Suns at number four including Jackson, Johnathan Issac, and Jayson Tatum. If McDonough believes that the position can be upgraded, regardless of which small forward(s) might be available, then it is possible the Suns look most at upgrading the small forward position, over any other spot on the roster.