While I did not check every name, I did use bb-ref's Play Index to pull up players with at least 5 hits in a game during their first 50 games. Unfortunately, this only goes back to 1913 but I did find a former Red Sox player, then with the Indians who got five hits in his 12th career game: Joe Vosmik, April 18, 1931. He was born April 4, 1910.
I didn't feel like going through all 92 names, especially as there were so many prior years missing.
I didn't feel like going through all 92 names, especially as there were so many prior years missing.