After Ken Lolla left the University of Akron in December 2005, the Zips hired Porter as head soccer coach.

After taking the Zips to two consecutive Mid-American Conference titles, and being named the 2007 MAC Coach of the Year, Porter signed a two-year contract extension in June 2008.

Following Akron's near-perfect season of 2009, Porter was rumored to be in talks with Major League Soccer club D.C. United about their vacant head coaching position.

[6] Under Porter, the 2010 Akron squad captured the NCAA Men's Division I Soccer Championship, defeating the Louisville Cardinals, 1–0.

[8] His first task was attempting to guide the U-23 team to a successful qualifying run in March 2012 for the 2012 Olympic Games in London; however, following a 2–0 loss to Canada and a 3–3 draw with El Salvador, the Americans were eliminated.

[12] In 2015, the Timbers once again reached the MLS Cup Playoffs, setting a new single-season club record in wins (15), while leading the league with 13 shutouts.

[13] From 2013 to 2015, Porter helped guide the Timbers to the fourth-most points (159) among all MLS clubs, behind only the New York Red Bulls (169), Seattle Sounders FC (167) and LA Galaxy (165).

On October 10, 2022, after missing consecutive post-seasons — including a loss on the final day of the 2022 season — Porter was fired as Crew head coach.

[18] On December 19, 2023, the New England Revolution announced that it had appointed Porter as its head coach, filling the void left by Bruce Arena several months prior.