Casey Stoney will step down as the head coach of Manchester United Women at the end of the season after three years in the role following a fourth-place finish in the Women's Super League.
Stoney, 38, will step down from her position at the end of the current campaign after failing to qualify for next season's Champions League. United finished a point behind Arsenal to miss out on qualification.
Stoney took charge of the club after they reformed as a senior side in 2018. The former England captain led the side to an immediate promotion into the WSL in her first season and then secured consecutive top-four finishes in the English top-flight.
It is understood that Stoney has become increasingly frustrated about the club's training facilities and other infrastructure issues in recent months.
Manchester United Women moved to the club's main training base in Carrington earlier this year but had to adapt their schedule around Ole Gunnar Solskjaer's men's side, mainly due to Covid protocols.
San Diego, who are expected to enter the National Women's Soccer League (NWSL) as an expansion team in 2022, are interested in hiring Stoney as their head coach. The newly-formed side after a relocation from Sacramento have former USA head coach Jill Ellis as head of team operations.
"It has been an honour to lead the women's team at this great club and this has been an incredibly tough decision," Stoney said.
"Having come on board to start the team from scratch, then winning the Women's Championship in our first season, we have now successfully established the team as a force in the Women's Super League. I have loved leading this group and I am proud of what we have achieved together.
"However, after a difficult season with disruption caused by the pandemic, I now feel the time is right to take some time away and for someone else to come in and lead the team on the next stage of its journey. I want to thank the club, all of the fantastic staff, the fans, and most of all the players, for the incredible experience we have shared over the past three years."
United, who have had considerable injury problems this term, were unbeaten in their first 10 WSL games of the campaign and leading the table at the start of 2021 before slipping down the rankings.
Last week Stoney, a nominee for WSL manager of the season, said "not getting Champions League football for me is a personal failure".
The club say they are in the process of recruiting a new Women's head coach and this will be announced in due course.
United executive vice-chairman Ed Woodward said: "As a club we are intensely proud of our women's team and we have invested considerable resource to make it a success. Casey has been a driving force behind that success since she joined us in 2018. She has been an inspiration to her players and staff, fans, and to all of us. I know I speak for everyone in thanking her for her unstinting hard work and dedication and paying tribute to her achievements."
Stoney will remain in charge for the final game of the domestic season at home to Leicester City in the Women's FA Cup on Sunday.