A 4-0 defeat against Tamworth on Tuesday night was their sixth from 12 league games so far this season, leaving them 18th in the table.
And the Glassboys have decided to act, with Yates leaving the club by ‘mutual consent’ ahead of their trip to Royston Town on Saturday.
A statement from Stourbridge read: “Following a meeting between Andy Pountney and Andy Bullingham, on behalf of the board of directors, and Mark Yates, it has been agreed between all parties that Mark, along with his backroom team of Neil Howarth and Gavin Hurren, will be leaving the club by mutual consent with immediate effect.”
Stour had failed to win any of their opening nine league games but after beating Hitchin Town 3-0, it looked like things might have been about to improve.
A 1-1 draw with AFC Rushden & Diamonds followed, but the big loss at Tamworth proved to be the final straw.
Glassboys chairman Pountney added: “The board of directors would like to thank Mark and his team for all their hard work and efforts since taking charge in February 2020, particularly during these Covid-19 affected times.
“We sincerely wish Mark, Neil and Gavin all the very best for the future.”
Stourbridge say they will make further announcements ‘in due course’.
Also in the division, Hednesford Town are looking to keep up their unbeaten home record on Saturday as they host Redditch United.
Keenen Meakin-Richards’ side currently sit sixth in the table while Rushall Olympic, in eighth, are heading to Biggleswade Town.
Stafford Rangers, in the Northern Premier, welcome Gainsborough Trinity to Marston Road.
In the Northern One Midlands, leaders Halesowen Town head to Yaxley, and second-placed Chasetown host Histon.
Sporting Khalsa, meanwhile, make the short trip to Sutton Coldfield Town.
And in the FA Cup fourth qualifying round, Kidderminster Harriers head to Bedfont Sports.