Earing was an unused substitute for the third League Two game in succession as the Saddlers lost 1-0 at table-toppers Leyton Orient on Saturday.
Flynn insists the 23-year-old – one of last season's top performers – is building his fitness up following an Achilles issue and will play at Cheltenham Town in the Papa John's Trophy tomorrow night.
"Jack'll have an opportunity on Tuesday," said Flynn.
"Don't forget, he missed a lot of pre-season and he struggled in the West Ham game against their kids.
"That told me he couldn't do two games in three days at the minute, because he's playing catch-up.
"So, I spoke to Jack. He's just got to keep working hard and he'll get an opportunity on Tuesday, no doubt."
Flynn, meanwhile, has called for Walsall to stop their lapses in concentration after the defeat at Orient made it nine games without a win.
"We're not good enough in both boxes. I mean for the duration of the game," added Flynn.
"For long parts of the game, we're showing we can do it. It's just that lapse of concentration.
"It's costing us. It's as simple as that."