Neil expressed his desire to leave Wearside on Friday morning and said his goodbyes at the Academy of Light before travelling to Staffordshire to finalise the move.
Sunderland’s Sporting Director Kristjaan Speakman has said Neil signed an improved 12-month rolling contract at the Stadium of Light earlier this month, and that a new proposal was made after the Scot expressed his desire to leave.
“First and foremost, we want to thank Alex for his contribution to Sunderland AFC,” said Speakman in a club statement. "The impact he made is clear and he played an integral role in our promotion last season.
"Despite signing revised terms earlier this month and receiving an offer to further improve his contract on Friday, Alex felt this was an opportunity that he wanted to pursue.
"We are extremely disappointed by his departure, but we ultimately respect his decision and we wish him well. The process to appoint a new Head Coach is underway and we will provide a further update to our supporters shortly.”
Here, though, we take a look at the early contenders to replace Neil at the Academy of Light:
13. Gus Poyet
The former Sunderland manager nearly took the job for a second time before the appointment of Lee Johnson. Photo: Charles McQuillan
14. Duncan Ferguson
The fiery Scot is now a free agent after leaving Everton and has been linked with the job previously. Photo: LINDSEY PARNABY
15. Lee Cattermole
The former Sunderland midfielder is now a youth coach at Middlesbrough but has been mentioned by fans as a potential Alex Neil replacement. It would surely be a risk, however. Photo: Charlie Crowhurst
16. Daniel Farke
Daniel Farke is currently the manager of German Bundesliga club Borussia Mönchengladbach Photo: Alexander Hassenstein