And the Scot reckons the division could be even stronger next season.
Ferguson, who twice guided Peterborough United to promotion to the Championship, has commented several times this season on how the playing budgets of the leading sides in League One are now higher than ever.
He says that is reflected in the quality of the competition.
And with Sunderland, Birmingham City and Hull City among the clubs currently in danger of dropping into the third tier, he says the standard could go up again next season.
“I think this league is as strong as I can remember it,” said Ferguson. “I think it’s a mini-Championship, I really do.
“It’s sort of filtering down for me.
“Obviously there’s a long way to go, and nothing is decided yet, but you only have to look some at the teams that could possibly come down.
“It could be incredible in League One next year. That’s maybe jumping ahead of the game.
“Wigan and Rochdale did fantastic for the league in the FA Cup, and Wigan in particular are having a fantastic season. Paul Cook’s done a great job there.
“For them to beat Manchester City was probably the result of the season for anyone this season, you have to say.”
Rovers dropped a place to 15th and saw their safety cushion above the bottom four cut from six points to five as a result of Oldham’s win at Scunthorpe.
Following the postponement of Saturday’s home game with Bury, Rovers return to action at Southend United this weekend. The Shrimpers suffered their first defeat under new boss Chris Powell at the weekend, losing 3-0 at home to Walsall.