Sentence:  Ryne Duren and Roland Sheldon , a rookie righthander who posted a 15 - 1 record last year for the Yanks ' Auburn ( N.Y. ) <WSD>farm</WSD> club of the Class - D New York-Pennsylvania League , are the probable rival pitchers . 
Meaning of the word marked with <WSD> tags:  a minor-league team that is owned by a major-league team (especially in baseball)