When you talk sideburns, and are dealing with baseball - the player that should come to mind is of course Don Mattingly.
Homer At The Bat is probably my favourite Simpsons episode of all time, and the classic joke about Mr. Burns wanting Mattingly to shave his sideburns is great.
Based on the real life incident, Mattingly was benched by Yankees management in 1991 for not cutting his mullet. Yeah, sometimes real life can be weirder than fiction.
Today we have a bunch of Mattingly cards - some with 2, 3 or 4 copies, but the above covers it all. Just a couple keepers for my set builds - 1988 O Pee Chee which honestly, being in Canada, I still have never really seen a lot of, and 1990 Upper Deck because I have the error version which doesn't have the copyright, but am building the set, so getting a correct version for that purpose works too.
14 years, all with the Yankees, and a Hall of Fame ballot appearance for 15 years, though never above about 25%, a great player, just not quite HOF.