Theophylact of Ohrid — as excerpted in the Catena Aurea on Mark 15:20-28

“Now John says that He Himself bare His cross, for both took place; for He first bore the cross Himself, until some one passed, whom they compelled, and who then carried it. But he mentioned the name of his sons, to make it more credible and the affirmation stronger, for the man still lived to relate all that had happened about the cross.”