"The Surgeon has looked at Mike and we also sent him for an MRI scan, and between the two of them they've said there isn't much wrong, so that's good news," manager Richardson told the club's official site.
"I think we are looking at two or three weeks out of action, which is better then we feared but also disappointing as Mike has been a real star in the last few weeks - but we'll battle on.
"As well as the ligament damage, he might have slightly injured his knee, but it doesn't look too bad and we'll assess his progress this week when he comes to the ground on Saturday."
The full damage to Whitlow - and the time he's likely to spend on the sidelines - should become clear in the next week or so.
After an extremely poor start to his Notts County career under previous manager Gary Mills, the former Bolton and Leeds defender's performances have improved beyond measure since Mills' departure and the appointment of Richardson in November.
The skipper has led from the back and has been a major help to his younger team-mates both on and off the field. We wish him a speedy recovery.
In Whitlow's absence, 19-year-old Kelvin Wilson and Julien Baudet will start in the centre of the defence for tomorrow's tie at home to Scunthorpe.