There has been much controversy recently about the supposedly catastrophic decline in the percentage of major league baseball players who are African-Americans. For instance, ESPN has a story lamenting the fact that, this year, only 8.2% of MLB players are black Americans, the lowest percentage in two decades. Baseball does indeed have a long history racial discrimination against black players, to some extent continuing even after Jackie Robinson broke the color line in 1947. But I don't see any serious cause for concern in the current numbers.
First, the figure of 8.2% is only modestly lower than the percentage of African-Americans in the current US population (about 12.7 percent). Moreover, even this comparison is misleading because some 28% of MLB players are foreign-born, including a large number of black players from Latin America. African-Americans are 11.4% of all American-born players in the major leagues, a figure very close to their percentage in the general population. The rapid rise in the number of foreign-born players (many of whom are black themselves) has lowered the percentage of African-American players, just as it has for other American-born players. Back in 1988, only 11% of MLB players were foreign-born, compared to 28% today. The percentage of African-American players has also declined because of the increasing appeal of basketball and football to the top black American athletes (a source of competition that is not a factor in the Latin American and Asian countries that produce most foreign-born MLB players). Several decades ago, football and basketball stars earned much less than top MLB players. Not so today.
Obviously, the fact that African-American players in MLB are represented in rough proportion to their percentage of the overall population does not prove an absence of discrimination against them. However, there is little evidence of systematic racial discrimination in recent years, and indeed most of the new foreign players who have to some extent displaced both black and white Americans are themselves nonwhite. Individual instances of discrimination probably still occur and should be remedied. Overall, however, I see no reason for great concern here.
One could also try to justify concern about the declining percentage of African-American players because of the need for diversity, even in the absence of discrimination. However, MLB players today are a more diverse group than ever before - precisely because of the influx of foreign players. I'm not convinced that racial and ethnic diversity (as opposed to player quality) should be a major objective in player development. But even if it should, today's MLB - with its numerous players of all races from Latin America and the Far East - is doing pretty well. It's a lot more diverse than it ever was in the past, and considerably more so than our other major professional sports leagues.
UPDATE: I should acknowledge that it may be reasonable for MLB teams to be concerned that they are no longer getting as high a percentage of the best African-American athletes as in the past - primarily a result of competition from basketball and football. However, there is no reason to view this issue as a matter of broader social concern. And even from the baseball front offices' point of view, there is no reason for them to worry about losing this talent pool than any other of comparable size. White American athletes, for example, are also less likely to choose baseball over other sports today than in the past.