Agbonlahor will be out of action for four to five weeks with a medial ligament injury suffered during the pre-season tour of America, the club have confirmed.
Dunne will be sidelined for six to eight weeks with a groin setback which he sustained while in European Championship action with the Republic of Ireland.
A Villa statement read: "Gabriel Agbonlahor will be sidelined for a further four to five weeks with an injury to his knee sustained against Chicago Fire after a scan confirmed medial ligament damage.
"Richard Dunne will also be out of action for six to eight weeks, having undergone a procedure on a groin injury which he sustained and was not dealt with during the European Championships."
Source: PA
Source: PA