Diamond has a foot injury and is the only doubt in manager Mark McGhee's 19-man squad for the clash after winger Sone Aluko returned to the club to prove his fitness.
The winger defied the club by joining up with the Nigeria Under-20 squad ahead of the forthcoming World Cup despite his club's concerns over an Achilles problem, but has now returned and has been passed fit to feature.
Aberdeen (from): Langfield, Foster, Ifil, Considine, Mulgrew, Kerr, Crawford, McDonald, Pawlett, Duff, Fyvie, Miller, Mackie, Maguire, Nelson, Young, Paton, Aluko, Grassi.
