Tony Philliskirk will take caretaker charge of managerless Oldham for the League One clash with Yeovil.
Paul Dickov resigned as boss over the weekend after Walsall condemned Latics to an eighth loss in nine league matches.
After key members of Dickov's backroom staff were placed on gardening leave on New Year's Eve, youth team coach Philliskirk stepped up to reserve team duties and helped out with the senior squad that now also falls under his remit.
"Tony Philliskirk is a stalwart of the club and has been around for the 10 years that I've been there," Oldham chairman Simon Corney told BBC Radio Manchester. "He's good as gold, he's always willing and helpful.
"We know the drill, we've had to do it before, Tony comes in, we'll do the training and he'll get on with it. He'll do team shape, I guess, on Tuesday as well.
"And we've got some experienced pros there now. Paul Murray's there, he'll help out with one or two other senior pros.
"Cliff Byrne's been around the block. They'll get it done. The club's not in the ideal situation, we know that, but like everyone else we have to move on."
Despite the glowing endorsement, Corney insisted Philliskirk would not be considered for the role on a permanent basis.
He added: "Tony does a great job with our academy, we know that, and that's going to take a lot of concentration over the next few years.
"Tony is going to stay in that department. He will always help out but he won't be applying nor will he be asked to become the permanent manager."