As a junior, he went 6–4, 2.38 ERA (30 ER/113.2 IP) in 17 starts for the Privateers, and was voted the Sun Belt Conference Pitcher of the Year.

In the fall of 2004, Diamond made a name for himself in an obscure Instructional League game during which he tripped and fell on the mound while attempting a pickoff move.

Diamond then threw his next pitch three feet behind the hitter at the plate and then delivered nine consecutive strikes to punch out the side.

On September 21, 2009, the Cubs designated him for assignment, making room for Tyler Colvin, never throwing a pitch for any team in the system.

[3] The Minnesota Twins signed Diamond to a minor league contract on June 20 and assigned him to Triple-A Rochester.