I can practically guarantee that at some point, some twenty-second century Foucault-type historian will write a thesis about how the debate and policies about steroids in MLB quaintly prefigured the radical changes that would follow in professional sports. For, whatever one thinks of steroids and steroid users, they are just the very beginning and the future will offer ways to alter and enhance athletes and human beings that are, at this point, completely unimaginable.
It might, for example, become possible to graft the muscle memory from a Sandy Cofax directly into the brain of an aspiring athlete, thus teaching them pitches in hours that otherwise would have been learned over an entire career. Perhaps, vast advancements will be made in the field of prosthetics, and the next three hundred game winner will do it in record time with an untiring robot arm (purists will suggest that he get an asterisk). Modern scouting, vastly more involved than anything that has existed before, will seem antiquated and vague when players have earpieces, or even screens projected onto their sunglasses, not merely giving them information on the history of the opposition, but also calculating the trajectories of balls, as they are hit in real time, adjusting for the wind. Robotic eyes (think Terminator) might lead to the re-birth of the .400 hitter.
The very nature of the ball player could change: the future might offer (hopefully) the opportunity to see an entire squad of cloned Ty Cobbs facing off against an entire squad of Bob Gibsons. At some point someone will isolate (or think that they isolated) the “clutch hitter” gene, and the next A-Rod will be guaranteed by the lab to hit with runners in scoring position, or you get your money back. Parents, frustrated in their own careers, will spend evenings trying to decide weather their unborn outfielder will hit for power or average, and weather they should spring for the speed gene, or put all their money in hand-eye coordination—it would be nice to get the leadership trait, but that one costs extra.
Exactly what will happen, and how it will be integrated into baseball, is of course ridiculous to attempt to predict. There will always be a minor culture of cutting edge modifications being illicitly introduced in sport; a crisis of a different order will occur if and when some form of modification (such as gene therapies, or prosthetics or something else entirely) becomes pervasive in the general population. Once people in general have become modified, the debate about what sort of modifications will be acceptable in athletes will take on a new dimension and will probably be followed very shortly by a new home-run record (and stolen base record, and life time batting average, etc.).
Of course, putting on the Twilight Zone-goggles, it is not hard to imagine a future where hormone and gene therapies, prosthetics, and mechanical implants have endowed the general population with supper-human physical abilities, and athletes are the only segment of the population that is left in their ‘natural’ state. Kept as some reminder of the ‘original’ humanity for the general population, these beings will compete at twentieth century games in twentieth century bodies: over time, their relationship to the evolving species will more closely resemble that of horses to breeders, trainers and jockeys.