Negro league umpire Henry Moore advised Newark Eagles' owners Abe and Effa Manley to give Doby a tryout at Hinchliffe Stadium in Paterson, which was successful; Doby joined the Eagles in 1942 at the age of 17 for $300. The contract stated Doby would play until September when he would start classes at college; to protect his amateur status he signed using the alias "Larry Walker" and local reporters were told he originated from Los Angeles, California. On May 31, Doby appeared in his first professional game when the Eagles played against the New York Cubans at Yankee Stadium. In the 26 games where box scores have been found, Doby's batting average was .391. Doby recalled a game against catcher Josh Gibson and pitcher Ray Brown of the Homestead Grays: