We have fully committed to speed and skill. Other than EJ we have no big bodies on D
The NHL roster does have a lack of a huge RHD PK'ing type, but the AHL roster definitely needed a RHD puckmover, especially considering that the 3 LHD's that figure to play most of the year in the bottom 4 are terrible with the puck (Gilbert, Middleton, Englund). If and when MacDonald gets called up to the NHL you have even less puck-moving ability in that group.
It's also worth bearing in mind that whilst Gross might not have much NHL upside, it's still important to fill your AHL lineup with guys who can play the style that the Avs want them to play in order to give the prospects the chance of having a seamless transition to the NHL. It's much easier for prospects like Bowers, Ranta, Foudy, etc to jump into the NHL on a transition-heavy Avs team if they've already been playing that sort of game with good PMD's in the AHL.
MacDonald -- Barron
Gilbert -------- McKeown
Middleton ---- Gross
Englund ------ Clurman