Argentina lock Mariano Galarza's debut for Gloucester will be delayed after he underwent shoulder surgery.
The 27-year-old sustained the injury in last weekend's Rugby Championship victory over Australia and had an operation on Wednesday.
He joined Gloucester from Worcester in the summer, but did not link up with David Humphreys' side until this week.
The Cherry and Whites have not put any timescale on how long the forward is likely to be sidelined.
But in a statement, the club said: "The operation was successful and Mariano will now follow an intensive rehabilitation programme, which will enable him to return to full fitness as soon as possible."