As any good collector would tell you, the 1987 Topps design practically jumps off the screen. The card in the first shot is unmistakably a Philadelphia Phillies catcher. A quick search shows that this is indeed 1987 Topps John Russell, getting his gear ready at Spring Training. He looks a little unhappy, probably because he has to report earlier than the other position players.
It's strange that a handful of commons made up this group, but that's only the beginning. Here's the problem: This season of the series takes place approximately at some point in 1982. Season 1 began in 1981. Reagan has recently taken over as President, and is still in his first term. I'm sure there is some database out there than can more accurately pinpoint the date of the episode, but that's not too important. Somehow, inexplicably, this kid owns baseball cards that haven't even been produced yet. This is a SERIOUS ERROR that should cancel out all of the accolades this show received during its run.
Hyperbole aside, what I'm guessing happened here was that the production designer wanted to give an authentic look to the boy's bedroom. A production assistant was likely given the task of finding some baseball cards to stick on the bed, so he or she ran to Target, passed over the new packs, since those would be too obvious, and grabbed a Fairfield repack box because the cards looked older and fit the '80s vibe. That's my best guess.
"In Mother Russia, baseball cards collect YOUUUUU!"