As a collegiate player, Diehl played in two NCAA Championships, and was a four-time all-conference selection. As a coach, his women's team won five consecutive Centennial Conference Championships from 2002-06 and has produced the conference’s individual champion in four of those years. Diehl has also sent a golfer to the NCAA Championships in 2004 and 2005, bringing home a pair of top-10 finishes.
In 2009, he returned his team to the top of the conference, winning a record sixth title before once again making it back-to-back crowns with No. 7 in 2010. For the latest title, his team overcame a three-shot deficit after the first round to win by one stroke on Sunday – the closest championship victory in conference history.
In addition to his duties at McDaniel, Diehl also serves as Director of Instruction for the NIKE Golf Coaches School. His students have won on both the collegiate and state amateur levels, including the New Jersey State Women’s Champion.
Diehl is married to the former Katie Haley ’99, who still holds the distinction of all-time leading scorer in Green Terror women’s basketball program history. In June 2011, Katie gave birth to the couple’s first child, Sean. The couple added a daughter, Ryann, in February 2013.