No matter how many signs you put up, no matter how many warnings you give, there are always those in life that will ignore the warnings to keep off the court!
Well on this occasion at the Miami Open, it was an unexpected visitor that brought a temporary halt to proceedings in the first-round match between Jiri Vesely and Tommy Haas – a giant iguana!
The uninvited visitor perched itself on top of the scoreboard during the final set with the score at 3-3.
Futile attempts were made to shift the lizard with a towel, while a clearly unamused Vesely refused to carry on playing despite the umpire pleading: "It's not a dangerous animal".
Veteran Haas has seen plenty during his career with adverse weather or injuries often causing delays, but even the 38-year-old will never have encounter such a strange turn of events.
And the German was not about the pass up the opportunity to have a little fun as he took out his phone to stop for a selfie with the new fan favourite.
"Maybe the iguana got the note that this is most likely the last time I'm playing here, and he wanted to say 'hi' and take a peek or something," Haas said.
"I don't know, but it was pretty cool. Of that size, I don't think I've ever experienced that.
"I don't know where he came from and why he wanted to come out on Court One and kind of say hello to everyone."
Eventually the match was finished with Vesely regaining his concentration to progress 6-7 (5-7) 6-3 7-5.