Johnson has until next Monday to decide whether he wants to be considered as a candidate to continue in the role after a disappointing World Cup.
The RFU have commissioned a review of their elite set-up, led by Fran Cotton while the likes of RFU rugby operations director Rob Andrew and former national captain Will Carling have raised questions over Johnson's future.
Current England skipper Lewis Moody has thrown his weight behind his former Leicester team-mate - and Croft agrees.
"The fact people are questioning Johnno being manager is pretty disgusting," he told BBC Radio Leicester.
"I think he is the ideal man for the job. I don't think any other team in the world has such a prominent figurehead. Hopefully he will decide to stick with the job."
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