Drain pineapple, reserving juice. Combine 2 tablespoons pineapple juice, drained pineapple, green onions, and next 6 ingredients. Set aside.
Place fillets in a grilling basket coated with cooking spray. Place grill rack on grill over medium-hot coals (350° to 400°). Place basket on rack; grill, covered, 5 minutes on each side or until fish flakes easily when tested with a fork, basting frequently with reserved pineapple juice.
Place a lettuce leaf on bottom half of each roll; place fillets on lettuce. Spoon 3 tablespoons pineapple mixture over each fillet; top with remaining roll halves. Using a slotted spoon, serve remaining pineapple mixture with sandwiches.