Frank Yallop resigned as the coach of Phoenix Rising on Monday, less than a month into the USL club's season and in the midst of its bid to move to Major League Soccer.
The move comes one day after the club introduced former Chelsea star Didier Drogba as a new player and executive.
The Arizona city is among a group of a dozen U.S. locations hoping to be awarded one of four MLS expansion bids either later this year or thereafter.
Phoenix had won its past two games after starting the season with two defeats, but the club said Yallop wanted to spend more time with his family after commuting from Northern California for the past year and a half.
The club's lead owner, Berke Bakay, told ESPN FC that the Yallop's decision came as a surprise to everyone, including Drogba.
"Didier was as surprised and disappointed as we were that Frank is unable to continue coaching our Club," Bakay wrote via text message. "But, we all respect his decision to put his family first.
"Didier's focus will remain on improving our team as a player and assisting our MLS expansion team ownership group as a co-owner. Frank will be helping with our international search for a new head coach."
Yallop's assistant Rick Schantz will lead the team on an interim basis until the search for a permanent replacement is completed.
"Helping set the stage for success at Phoenix Rising FC has been among the most enjoyable accomplishments in my career," Yallop said in a statement. "The timing is perfect here for me to step aside and move back home with my family.
"I want to thank our talented players for believing in our vision, and our extremely dedicated ownership group. I believe there is no other club better positioned for expansion to MLS."
Yallop previously coached in MLS with the San Jose Earthquakes, LA Galaxy and Chicago Fire.
ESPN FC's Jeff Carlisle contributed to this report.