According to one aspect of the invention, a combustor assembly for a pair of adjacent combustors includes a first passage formed in a liner of a first combustor and a flow sleeve disposed outside the liner of the first combustor, wherein the flow sleeve includes a window and a second passage aligned with the first passage. The assembly also includes a cross-fire tube disposed in the first passage to provide fluid communication between the first combustor and a second combustor and a retention clip disposed through the window to urge the cross-fire tube against an outer surface of the liner to enable the cross-fire tube to receive fluid through the first passage.