Wing Louis Rees-Zammit is a doubt for Wales' opening Six Nations campaign game against Ireland on 4 February.
"He will certainly be out for a spell," Gloucester head coach George Skivington said.
"It could range from two weeks to six months, and on that basis he could be joining the Six Nations late."
Skivington added: "He is unlikely to need an operation but his ankle is in a boot with the prognosis not forthcoming because we haven't been able to receive the scans this week because of hospital delays."