McStay is believed to have made an expression of interest to the county board in recent days ahead of tomorrow evening's deadline.
The former Roscommon manager has teamed up with Rochford and former coach Donie Buckley, with Liam McHale and Damien Mulligan also on board.
McHale is a brother-in-law of McStay and was involved with him for three years in Roscommon and is currently Belmullet manager, having replaced Mulligan.
Mulligan took Belmullet to last year's county final, which they lost to Knockmore but it was significant progress nonetheless.
The assembly of such a strong management team packed with recent inter-county experience will leave it difficult for the Mayo county board sub committee, tasked with conducting the process in the coming weeks, to turn down.
Rochford managed the Mayo team between 2016 and 2018, reaching two All-Ireland finals which were lost to Dublin by a point, one after a replay.
He has spent the last four years as coach to Declan Bonner in Donegal and was involved when they won the 2019 Ulster title. Earlier this week he was linked to Bernard Flynn's potential backroom team in Meath but that speculation was wide of the mark as the McStay management move, of which he was part of, has been in progress for some time.
McStay has been busy. with TV and print media engagements in the four years since he left Roscommon but, like Colm O'Rourke in Meath, is now prepared to put that behind him to manage his native county.
He was previously turned down for the position in 2014 when Pat Holmes and Noel Connelly were appointed on a joint ticket instead, an arrangement that only lasted a year before the players moved against them.
Buckley has been involved as coach to Monaghan over the last two seasons as part of Seamus McEnaney's management.
McStay suggested in a parting statement from Roscommon in 2018 that he wouldn't take on an inter-county management job again but the lure of the Mayo job is just too appealing.
Others being linked to position are Knockmore's back-to-back county title-winning manager Ray Dempsey and Mike Solan, manager of the U-21 side when they won the All-Ireland title in 2016.