Marin Cilic lost his cool while on the verge of a defeat in his Dubai opener as he went off at the chair umpire during the second set tie-break against Jiri Vesely. After Cilic missed a cross-court backhand, Vesely went 4-0 up in the second set tie-break and then Cilic went off at the chair umpire. Cilic wanted to know why the chair umpire needed an umbrella when he was already wearing sunglasses. The conditions in Dubai were windy and the umbrella was flapping during the fourth point of the second set tie-break. “Why?!Why?! Explain to me why you need the umbrella,” asked Cilic. “Why? You have sunglasses, you have the sunshade. And [even then] you have an umbrella! …