How this A’s prospect impressed during Arizona Fall League

This story was excerpted from Martín Gallegos’ A’s Beat newsletter. To read the full newsletter, click here. And subscribe to get it regularly in your inbox. Of the seven prospects who represented the A’s in the Arizona Fall League, Jack Perkins came away as arguably the club’s top performer. With the AFL schedule having wrapped up on Sunday, Perkins was nearly flawless over his time in the desert. The A’s No. 19 prospect did not allow an earned run over his team-leading 10 appearances for the Mesa Solar Sox, turning in a 15-6 strikeout-to-walk rate with a 1.22 WHIP and…