Connacht forwards Andrew Browne and Aly Muldowney have both picked up injuries ahead of the new season.
Browne, who sustained a meniscal tear to his knee, is due to see a surgeon today but is looking at four to five weeks on the sidelines.
Second row Aly Muldowney will be out of action for up to five weeks following an ankle sprain.
Meanwhile, winger Matt Healy suffered a small hand fracture and is now looking at a four-week rehab programme, while centre Dave McSharry will be forced to sit out training this week due to a mild ankle sprain.
In better news, Jake Heenan, Ronan Loughney and Jack Carty have all resumed full training and are in line to feature in Connacht's final preseason game against Wasps on 23 August.
Robbie Henshaw, Kieran Marmion and Rodney Ah You are all involved in Ireland's three-day training camp this week in Carton House and will return to Galway on Wednesday.