Fabio Fognini apologised after saying Wimbledon should be bombed during his third-round defeat by Tennys Sandgren.
The volatile Italian appeared frustrated that his match had been scheduled on the small Court 14 and was heard saying in Italian: "Damn English. I wish a bomb would explode on this club. A bomb should explode here."
Wimbledon was hit by a bomb during World World II that damaged the Centre Court roof.
At his post-match press conference, Fognini said: "The court was not really good. Most of the time when you're on court, you're frustrated.
"For sure I was not happy about my performance today because I was knowing I have a lot to win in this case, because I think I have a good chance to win.
"Something happened on court. If somebody feels offended, I say sorry. No problem."
It is far from a first offence for Fognini, who was fined a then record 27,500 US dollars (approximately £21,600) at Wimbledon in 2014 for a series of offences during a first-round match.
Pointedly, meanwhile, he is also under the threat of a grand slam ban after using misogynistic and abusive language towards a female umpire at the US Open in 2017.
Fognini's conduct was deemed a major offence by the Grand Slam Board and he was given a suspended ban of two slam tournaments covering two years as well as a fine of more then £70,000, half of which was suspended.
Wimbledon must now decide how severely to punish Fognini for this latest act.
The world number 10 also took a medical time-out for treatment to a bloodied hand after punching his racket to the court in frustration.
American Sandgren is through to the fourth round at Wimbledon for the first time and will take on his countryman Sam Querrey on Monday.