Umpire Arnaud Gabas has had surgery to repair a fractured eye socket after he was hit with a ball during Britain's Davis Cup win over Canada last week.
Canada's Denis Shapovalov struck the ball in anger and hit Gabas during his game with Kyle Edmund, defaulting the match to hand the tie to Great Britain.
The International Tennis Federation said the 17-year-old's actions were "unintentional" but fined him £5,600.
The ITF says the surgery was successful and Gabas is now recovering at home.
The Davis Cup World Group first-round tie in Ottawa was poised at 2-2, with Edmund leading 6-3 6-4 2-1 in the final match, but Canada's hopes ended when Shapovalov was disqualified.