The women's eight-strong team will compete in the South Island team event in Ashburton this weekend while the men's side will be out to defend its South Island title at Westport.
Greig last competed for Otago in the interprovincial at St Clair in December 2012 but has made herself available after qualifying top and winning the matchplay title during the weekend.
There is little doubt her wealth of experience and current form will give the team a boost which has been in a rebuilding phase for the past two years.
Men's selection convener Greg Johnson and his team have recognised the matchplay ability of Ross who was a key member of the Otago junior octet which won the junior interprovincial title at Cambridge last month.
It was Ross' second appearance in the Cambridge event. He recored four wins and a half in 2014 and five wins out of six outings this year.
McEwan and promising junior Inia Logan are not available for the event at Westport this weekend which will give other players a chance to stake their claims for a top-five place in the teams for the SBS invitational and the interprovincial in Invercargill this year.
After his success during Labour Weekend, Chris Snow will play at No 3 and captain the team in McEwan's absence.
Otago teams
in playing order
Men: Nick Borren (Otago), Duncan Croudis (Otago), Chris Snow (St Clair) 6 captain, Brandon Hodgson (Otago), Fraser MacLachlan (Millbrook), Sungwoo Han (Wakatipu Junior), Ryan Bellamy (St Clair), Connor Ross (St Clair). Reserve: Harry Smith (Otago).
Women: Jo Hicks-Beach (Queenstown), Abigael Crawford (St Clair), Annabel Evans (Port Chalmers), Susan Greig (St Clair), Sally Shaw (Chisholm Links), Tracey Storer (Belleknowes), Robyn Chambers (Otago), Brenda Sutherland (Otago). Team manager Lisa Joyce will fill in as reserve if required.
