Ospreys trio Huw Bennett, Andy Lloyd and Luke Tait will all miss the start of the Celtic League campaign against Munster this weekend.
Wales hooker Bennett, who toured Argentina and South Africa in the summer, is suffering a hernia and could also miss the west Wales derby against Llanelli a week later.
Flanker Lloyd is also out for a fortnight with a hamstring problem while coach Lyn Jones is also keeping a close eye on lock Tait's neck strain.
'It's a blow but we have brought in a number of high-quality players to strength in depth to the the squad,' said Jones.
Meanwhile the Ospreys are considering a change in team name and playing colours for next season as they quiz supporters from Neath and Swansea over the future of the regional team.
Ospreys chief executive Andrew Donald said: 'The consultation will be exactly that - a listening exercise. We want to know from supporters what they think we've got right and where we could do better. We'll want to know what they think of the Ospreys' identity and branding, as well as obtain feedback on the Ospreys' future facilities.'
Nearly 40 players were involved in the first Wales Under 18 training session of the season. WRU National Performance Manager Gethin Watts is excited at the potential shown by the group and expects the Regional Under 18 Championship to hone their skills even further.