You mean playing three pro sports? Not possible.
The last person to play just two sports that I know of was Deion Sanders. He was not a good baseball player. It’s likely that if he wasn’t a star NFL player he wouldn’t have made the majors in baseball.
You have the problem with the player having to travel during times when the sports overlap. Teams play baseball anywhere from five to seven times a week starting in April during basketball season. How are you going to play baseball and basketball at the same time? Why would either team pay you to miss so many games due to scheduling conflicts?
Football is a full time job. You spend the week studying the upcoming game plan, practicing with the team, and recovering from the last game. You can’t recover if you’re flying all over the country to play in your other sports. You can’t attend meetings or work out coverage schemes on the practice field.
Sanders was able to get away with it because his value as a baseball player wasn’t that great. If he missed a game then it wasn’t the end of the world. At the same time, the Braves were able to say that they had a two sport player; Sanders’s name held a lot of weight, even if his bat didn’t. He was also skilled enough at football that he could afford to miss a practice or two. I still think he may have been even more effective had he just stuck to football and not been distracted.
Sanders got more mileage out of being called a two sport athlete than he did out of actually being one.