before The Simpsons appearance
Don Mattingly was arguably the best hitter in the game during the period of 1984 through 1989. By "Homer at the Bat" (early 1992), he was already coming off a couple down years (and in fact would not have another truly great season thanks to a bad back), but Donnie Baseball was still a popular face of the game, and the heart of the Yankees during that era.
Homer at the Bat
Classic Line: "I still like him better than Steinbrenner."
after The Simpsons appearance
Mattingly was able to grind out a few more years with decent numbers, though a far cry from his prime. Back pain forced him to retire after the '95 season, cutting short what was once a sure-bet HOF career. A lifelong Yankee beloved in New York, after being passed up to manage the only club he ever played for, wound up in Los Angeles helming the Dodgers.
Highlights from my Collection:
I had to cheat a little with the top custom card. I've been trying to stick to 1990-1992 card designs (occasionally slinking back into 1989), but Mattingly's 1993 Topps is somewhat of an iconic junk-era horizontal card, and works perfectly with the "action shot" screen grab from the show, fittingly a similar picture.
In another funny "The Simpsons predicted it" instance, Mattingly later had a real-life hair controversy where Yankees management forced him to cut his hair, and briefly benched him for not doing so. Many people thought the joke in the show was a reference to the incident, but "Homer at the Bat" was recorded a year before it happened. (UPDATE: More digging into this in the comments below.)
Looks like we got back-to-back Yanks here on the Fortnight, as tomorrow we take a look at the team's second-slacker: Saxy Boy, Steve Sax.