He had stamina issues again in the 3rd set today against LCW at the Dubai SS finals. On one of his lunges at the net, he looked extremely tired and the commentators made a note of it. Lucky for Viktor, he was playing against a 35 year old player who doesn't have stamina either. I don't see the same stamina issues with other players in the 3rd set, say Chen Long. Even if Chen Long goes through 2 difficult sets to reach the 3rd set, Chen Long rarely looks that tired.