It isn't uncommon for a newcomer to a team to have their number already represented by someone else important to the franchise.
Sometimes it is a player that is currently suiting up for the team, such was the case when Patrick Marleau became a Toronto Maple Leaf and asked Connor Brown if it was possible to take another number (Brown would eventually end up number 28). Other times a player's number happens to be the same as a player that has their number retired. Good luck trying to wear the #2 as a Yankee after the mark Derek Jeter left on the franchise. Sometimes a players number is so significant that people think nobody in the league should be allowed to wear it - just look at the kerfuffle that happened when Josh Ho Sang decided to suit up wearing Mario Lemieux's #66.
On Wednesday, Lauri Markkanen reportedly asked permission to wear the number 24 in a Bulls uniform to a hilarious player - cult legend Brian Scalabrine.
Scalabrine - endearingly (or sarcastically) nicknamed the White Mamba - is now a recognizable player for reasons not quite so admirable. He only played in 36 career games with the Bulls but he left his mark on the franchise based on the satirical fan following. He barely did anything on the court, but everyone seemed to love him based on his unique look and the fact that he just wasn't very good.
This makes the asking of permission that much more hilarious, but hey - you have to give credit where credit is due.