The trio were forced to withdraw from midweek internationals because of injury setbacks but should be ready for the trip to Ewood Park.
Agbonlahor withdrew from England's home game with France as a precaution after suffering a knock against Manchester United last weekend - his first start for six weeks after groin surgery.
Clark missed the game against the Red Devils with a calf injury and pulled out of the Republic of Ireland squad for the friendly against Norway. Dunne also sat out the Ireland international due to an ongoing knee problem.
Assistant manager Gary McAllister said: "After only two or three days training, I thought Gabby did fantastic for 75 or 80 minutes against Manchester United. That was great news. He has picked up a few little niggles that have made him pull out of the England squad but hopefully he should be fine for the weekend.
"Richard has been nursing a few body blows. As you can imagine he is always in the mix with tackles and headers so we've just been protecting him really. Ciaran is very similar but hopefully come the weekend the manager has a few more to pick from."