The Johnson family clash in an eagerly anticipated League One showdown on Tuesday night, with the Glovers eying automatic promotion and Latics scrapping for points to avoid relegation.
But Johnson Jnr believes the fact most of his playing career came under his dad's management at Huish Park and Bristol City can work in his favour.
"That's probably the one advantage I have got - I probably know his mind just as much as he knows his," he said.
"I can play the game in his mind which I think sort of counteracts his experience over me, the fact that I know him so well and I know the team so well.
"I know their team more than they know ours so there's two things, but Yeovil are a very good side - they're fitter than us, hungry, young."
Lee Johnson became the Football League's youngest manager at 31 when he succeeded Paul Dickov as Oldham boss last month - an almost inevitable career choice given the high regard in which he holds his father.
"I'm proud of the fact that he's had 850 games (as a manager) and been in pretty much consistent employment for 20-25 years in football," he added. "There's not many who can say that now.
"Also, he had a bang-average, if not nothing, career as a player. So it shows you how well he's done and how hard he's had to work.
"I remember the sacrifices. He went to be Cambridge United's reserve-team manager for 50 quid a week and that was our only income at the time. So I've got a lot of respect for what he's done for the family and the lengths he's gone to."
- Sports & Recreation