Bath will have to do without fly-half Butch James until November after he underwent surgery on his right shoulder.
The 31-year-old was hurt after going on as a replacement for South Africa during their Tri-Nations clash against Australia last month.
James, who helped the Springboks win the World Cup back in 2007, has now had an operation to stabilise the shoulder.
"It is always frustrating to lose a player of Butch's influence," said Bath head coach Steve Meehan.
"But we will make sure he receives the best care and attention to get him back with the squad as and when he's ready."
Bath have started their Aviva Premiership campaign with wins against Leeds Carnegie and London Irish, though their 20-13 triumph over the Exiles came at a cost.
England internationals Matt Banahan, Lee Mears and David Flatman and Scotland's Simon Taylor - all went off during the game at the Rec.
The quartet could be sidelined for Friday night's clash with Northampton, who currently sit a point behind leaders Bath in the table, at Franklin's Gardens.