Trading at Sports Direct International, owned by Mr Ashley, is expected to be strong as sales are boosted by stock bought by the group when it snapped up 20 of JJB's shops from administrators.
The City expects the group to be on-track for full year pre-tax profits of £207m - up from £154m the previous year.
At its half year, Sports Direct jumped to a record profit after enjoying a "significant" sales boost from the London Olympics and Paralympics.
Half-year revenues were up 22.5 per cent to just over £1bn amid strong growth in its 398 UK shops and branded sportswear division.