[7] In his sophomore year with Northern Arizona University, one of his lungs collapsed, and Estrada's career was brought into question.

In his junior year, Estrada opened outdoor season with the third-fastest 1,500m time in NAU history at the Mt.

At the 2011 NCAA Indoor Championships, finished fourth overall in a NAU indoor-record time of 13:29.01 for first All-America award on the track.

Redshirt year[clarification needed], Estrada ran a personal-best time in the 10K (27:32.90) at the Payton Jordan Invitational as an unattached athlete to earn his ticket to London.

[11][12] Estrada won his 2nd USATF Title[13] in Houston on January 18, 2015 by running the 7th fastest American half marathon[14] ever in 60:51.

[16] Diego Estrada finished on the podium in Providence, Rhode Island at USA Road 5 km championships on September 20 in 14:22.

Stephen Sambu faced off against Olympian Diego Estrada, the seventh-fastest American over the half-marathon distance.