The Ireland international had been expected to miss the rest of the campaign with a knee injury sustained against Bolton on April 1.
Indeed, Richardson admitted initial fears were that he would be sidelined for the best part of a year.
Thankfully, the news was far more positive, with McClean soon posting pictures on social media of him back in the gym.
And eagle-eyed fans would have seen him taking part in the pre-match warm-up at Portsmouth in midweek.
Richardson did his best to keep a lid on the prospect of a return to the fold at Shrewsbury on Saturday, where Latics still require a point to be mathematically certain of automatic promotion.
But he admits all options are still on the table, with his side winless in the last five.
"James is doing his rehab, and we're not going to pre-empt anything or rush anybody back," he said.
"We have a duty of care to the players first and foremost.
"If he's available and fit, he'll be the first one to put his hand up for selection.
"If not, he'll be there to support the lads as he was at Portsmouth."
Latics have come with one goal of clinching promotion in each of their last matches, only to have been denied.
And Richardson is expecting no favours from a Shrewsbury side that have nothing to play for - but will be as fired up as any other team.
"You can see all year the challenge our lads have faced," he added. "Teams are raising their game against us, like it's their biggest game of the season, so to speak.
"We've had to face that and match that all year and, for the large part, we've done that.
"If we manage to maintain our habits, our work ethic and our consistency, you usually get what you deserve after 46 games."
McClean was named in the League One ‘Team of the Year’ at the weekend, along with team-mate Jack Whatmough.