On July 23, 2002 Diggins was traded by the Dodgers along with Shane Nance to the Milwaukee Brewers for Tyler Houston and a player to be named later, who eventually was Brian Mallette.

He finished the season with the Double-A Huntsville Stars of the Southern League where he went 2–1 with a 1.91 ERA in seven games, all starts.

In 2003 Diggins began the season with the Double-A Huntsville Stars going 3–2 with a 2.36 ERA, all starts, before tearing the UCL ligament in his elbow.

On December 8, 2005 Diggins was selected by the Houston Astros in the Rule 5 Draft but never made an appearance in their organization.

After being released by the Houston Astros, Diggins signed with the Independent Windy City Thunderbolts of the Frontier League as a first baseman.